Update - 5.57pm: Paul Nicholls has finished with a double on the day courtesy of the Barry Geraghty-ridden Le Prezien (15-2) in the Johnny Henderson Grand Annual Challenge Cup Handicap Chase.
It means Gordon Elliott has been crowned leading trainer with eight wins, edging Willie Mullins, who took seven wins, to the honour.
Davy Russell has won the leading jockey title for the first time.
Russell and teenager Jack Kennedy both ended with four wins each, but Russell took the prize courtesy of more second-place finishes.
Update - 5.19pm: Blow By Blow gave trainer Gordon Elliott his eighth winner at this week's Cheltenham Festival when defying top weight in the Martin Pipe Conditional Jockeys' Handicap Hurdle.
The seven-year-old made all the running in the hands of Donagh Meyler to complete a double on the card for Elliott following the victory of Farclas in the JCB Triumph Hurdle.
The 11-1 shot was also a seventh winner at the meeting for owners Gigginstown House Stud.
Paul Nolan's Discorama came from out of the pack to claim second place, five lengths behind the winner. Joseph O'Brien's Early Doors was a length and a quarter away in third, with another Elliott runner, Sire Du Berlais, fourth as Irish horses took the first four places.
It also means Elliott matches Willie Mullins' record of eight Cheltenham wins in a single festival, set in 2015.
Elliott said: "He got a soft lead and fair play to the horse, he was a Grade One winner. He looked well-handicapped, but I thought the ground was too soft for him.
"What a week - to have eight winners. I can't believe it. We can enjoy it now."
Meyler said: "He was keen to the second and I got a soft lead out in front, but the horse was a Grade One bumper winner at Punchestown and it stood him in good stead.
"He was in his own comfort zone the whole way and I was able to fill him up. It made a big difference to get up that hill.
"They came at me from the second-last but the horse stuck his head out.
"It's great. I'm stuck for words."
Update - 4.36pm: Harriet Tucker performed an amazing feat in the saddle at Cheltenham as she overcame a dislocated shoulder to guide Pacha Du Polder to a repeat success in the St James's Place Foxhunter Challenge Cup Open Hunters' Chase.
The 11-year-old, trained by Paul Nicholls, jumped into the lead at the final fence, but Tucker - who was having just her second ride under rules - appeared in some trouble up the run-in and she confirmed on dismounting she had been forced to pop her shoulder back into place at the same time as striving for victory.
Long-time leader Top Wood rallied close home, but Pacha Du Polder would not be denied as he stuck on stoutly to score by a neck.
Barrel Of Laughs and Cousin Pete dead-heated for third place, three and a quarter lengths away.
Tucker said: "My shoulder half-dislocates sometimes when I reach it too high and coming up to the second-last, it half-dislocated and I couldn't push it back in, so I couldn't slap him down the shoulder to get him to go forward.
"I was pushing and praying that no one was going to beat me because I couldn't hit him anymore with my right hand, so I just had to keep pushing and screaming at him and he just got there."
Update - 3.37pm: Native River saw off Might Bite to make all the running in what was an epic duel for the Timico Cheltenham Gold Cup.
Third 12 months ago, the Colin Tizzard-trained Native River (5-1) went two places better to win in the hands of champion jockey Richard Johnson, who was landing the blue riband for the second time after Looks Like Trouble in 2000.
Native River and Might Bite, the 4-1 favourite, were the first two throughout and it was the former who proved stronger from the last fence to prevail by four and a half lengths. The pair were a further four lengths clear of 33-1 chance Anibale Fly in third.
Johnson said: "I'm speechless. He's been a fantastic horse for me and I was lucky to pick up the ride on him.
"He's just amazing. He jumps for fun. I was getting squeezed, but at the second-last and the last he just wanted it so much.
"I knew Nico (de Boinville, on Might Bite) was there and to be fair to Might Bite, he's run a hell of race, but I think we just outstayed him. They are two very brave horses."
He added: "Eighteen years (since Looks Like Trouble) seems a long time!"
Tizzard said: "It's unreal. The Cheltenham Gold Cup is everything in everyone's life and there's no pretending it's not. Richard Johnson was galloping as fast as he could and jumping as fast as he could all the time and the horse never let him down once.
"Might Bite came to him and I thought that was it, but he just powered away again.
"We've had a wonderful preparation with him, so you think something's going to go wrong in the race, but it didn't. His form has gone on from last year.
"I can't believe it. It doesn't get better, does it?"
Update - 3.07pm: Kilbricken Storm caused a 33-1 upset as he showed stamina in abundance to win the Albert Bartlett Novices' Hurdle at Cheltenham.
A first winner of the week for trainer Colin Tizzard and a first ever at the Festival for 19-year-old jockey Harry Cobden, Kilbricken Storm powered up the hill after heading long-time leader Fabulous Saga at the final flight.
Although the pack closed near the line, Kilbricken Storm was home and hosed as he scored by three lengths and a length from the Nicky Henderson-trained pair of OK Corral and Santini, who was sent off the 11-4 favourite.
Tizzard said: "It's fantastic. He just travelled really well, he was fifth or sixth and then just moved into it - I was waiting for the cavalry to come, and they didn't. You have seen it all week, they've been coming and grabbing the ones in front, but they didn't get him.
"He had pus in a foot (earlier this week) but it hasn't stopped him."
Johnson had made his intentions clear from the start of the extended three-and-a-quarter-mile test by setting off in front, but he was shadowed all the way by De Boinville and Might Bite.
They dominated proceedings all the way through and no other horse was able to get to them.
Might Bite, bidding to give Nicky Henderson an unprecedented treble after the victories of Buveur D'Air in the Champion Hurdle and Altior in the Queen Mother Champion Chase, appeared to be going the better of the two as they turned for home.
However, the King George VI Chase winner was just found wanting from the last, as the stamina of last season's Hennessy and Welsh National scorer kicked in.
Update - 2.17pm: Bridget Andrews landed her first success at the Cheltenham Festival when driving Mohaayed home in a driving finish to the Randox Health County Handicap Hurdle.
The 3lb-claiming conditional rider was embraced by her partner Harry Skelton, who rode stablemate Spiritofthegames into sixth place, when the horses pulled up after the line.
Sternrubin and Tigris River took the 24-runner field along until the serious end of the ultra-competitive contest and it was hard to call the winner at the final flight.
Mohaayed (33-1), trained by Skelton's brother, Dan, produced the best turn of foot to take the spoils by two and three-quarter lengths from Remiluc, with Whiskey Sour third and Chesterfield fourth.
Update - 1.38pm: Farclas opened his account over jumps with a gritty performance to land the JCB Triumph Hurdle at Cheltenham.
Second in both his previous starts, the grey gelding made it third time lucky as he gave trainer Gordon Elliott a seventh winner at the meeting and jockey Jack Kennedy a fourth in the ever-familiar colours of Gigginstown House Stud, who have also had a successful time this week.
Stormy Ireland made most of the running, but she was under pressure when falling at the final flight, as several horses had every chance.
Gordon Elliott adds to his Festival tally with an impressive Triumph Hurdle performance from Farclas. Elliott is now on seven wins.March 16, 2018
Farclas (9-1) stuck his head in front and kept up the momentum to hold Mr Adjudicator at bay by a length and three-quarters. The latter's trainer, Willie Mullins, was also responsible for the third, Sayo, who was three and a half lengths away.
Apple's Shakira, the Nicky Henderson-trained 6-5 favourite, was only fourth.
Kennedy said of the winner: "He's been running very well in his last two races and improving all the time. Gordon had him spot on today.
"He (Elliott) has done so well with these horses - it's unreal. He just leaves no stone unturned, his attention to detail is second to none."
Elliott said: "It's great, we're having an unbelievable week. I keep saying to the staff and owners that it's unbelievable, and it's a big thanks to everyone.
"On his first run he was beaten in a Grade Two, then he was beaten in a Grade One by the second (Mr Adjudicator), so there was only a good jump between them and the Irish form stood up."
The Irish tally for the week is now 16.
By Tommy Lyons
Last year’s Cheltenham Gold Cup winner, Sizing John, may not be here to defend his crown but trainer Jessica Harrington has an able deputy in the shape of Our Duke, who can land racing’s blue riband on the final day of another very successful Festival for Irish-trained runners.
A winner of his first two starts over fences, including a Grade One at Leopardstown’s Christmas meeting, he wrapped up a great season with a spectacular performance in the Irish Grand National.
This season began on a low note, when he picked up an injury on his return, but he showed signs of a return to form when fourth behind Edwulf in the Irish Gold Cup.
Having made a bad mistake at the second-last that day, Harrington felt the need for another spin over fences, which she gave him in the Red Mills Chase at Gowran Park.
He had to concede 7lbs to novice Presenting Percy in that race but came out on top to the tune of a length, and the form of that race could not have received a bigger boost when the runner-up posted a huge effort in winning Wednesday’s RSA Chase.
Jumping remains the only concern for Our Duke as he has shown he can handle testing conditions, and stamina is of no concern.
He has a touch of class which many of his rivals lack, and if he can put in a clean round of jumping he will be right there as they race up the hill.
Might Bite is one of Our Duke’s rivals who certainly doesn’t lack class.
He has ability in abundance and put in a remarkable effort to win last year’s RSA Chase. He all but threw away the race with his wayward antics after the last but picked up again to deny stable-companion Whisper.
Today’s longer trip is a concern, particularly in testing conditions, and he won’t get away with any quirky antics at this level. The problem is he is too classy to ignore.
Nicky Henderson is the leading trainer and Barry Geraghty the leading jockey in Triumph Hurdle history and they can combine to enhance their record by taking this afternoon’s renewal with Apple’s Shakira.
The filly won her only start in France and has added three more hurdle victories since joining the Seven Barrows team.
On the first of those three outings, she was heavily backed to beat then Triumph Hurdle ante-post favourite Gumball — and obliged with a considerable amount in hand. She had little trouble following up at the expense of Nube Negra, and again when beating Look My Way in late January.
All three wins were at Cheltenham, two of them over today’s course and distance. Henderson knows better than anyone what is needed to win this race, and he can claim a seventh victory in the race, and a sixth for Geraghty.
Gordon Elliott has enjoyed another memorable meeting and can take the Martin Pipe Conditional Jockeys’ Handicap Hurdle with Flawless Escape.
The five-year-old impressed in winning his maiden at Leopardstown’s Christmas meeting, when the final hurdle was omitted, resulting in a long run-in.
He won with a bit to spare that day and ran as well as could be expected when third behind Gold Cup hope Total Recall last time out, over three miles.
On that occasion, stable-companion Delta Work finished upsides, and that form looks particularly strong now, with the last-named winning the Pertemps Final here yesterday. There is certain to be plenty more to come from the selection, and he can take this competitive race at the expense of Deal D’estruval, who ran a super race in defeat in a hot handicap on his most recent start.
Santini can take the Albert Bartlett Novices’ Hurdle for trainer Nicky Henderson and jockey Nico De Boinville.
The six-year-old won a point-to-point in March of last year and made a successful track debut when beating stable-companion Chef Des Obeaux, who re-opposes, in a two-and-a-half-mile novice hurdle at Newbury in December.
The form of that effort reads very well in light of the runner-up’s subsequent exploits, but it’s the form of Santini’s recent form which is even more encouraging. In a Grade Two over two and a half miles on the New Course at Cheltenham, he got up late to deny Black Op by three parts of a length, with the remainder a long way back.
While it could be argued the runner-up went for home a little early, it was a great effort by Santini, and one which suggested he should appreciate the step up to three miles, which he gets today. If that proves to be the case, he will be hard to beat in a race which his trainer won with subsequent Gold Cup winner Bobs Worth in 2011.