Walsh's mount Abbyssial was in front when stepping right into the second flight, giving his pilot a shocking fall.
It was immediately apparent that Walsh was in trouble, as he got to his feet without putting any weight on his right hand.
It soon emerged that he had suffered a fracture of his humerus, as well as a dislocated shoulder, and was quickly removed to hospital in Gloucester.
Later in the afternoon, Walsh was operated on and it remains to be seen just how long he will be absent from the game.
And then there was Russell, who won the JCB aboard, rather ironically, the Gigginstown House Stud-owned Tiger Roll. Of course Russell's day was to get even better.
It has been well documented that he was relieved of his duties at the back-end of last year as first jockey to Gigginstown, over a cup of tea, by Michael O'Leary.
The rather surprising decision has never been explained, but with their new number one, Bryan Cooper, on the sidelines, having broken his leg earlier in the week, it was possible to infer O'Leary decided that “old friends” were best.
In any case, Russell was seen to good effect, producing Tiger Roll with a powerful challenge to sweep to the front going to the final flight.
This was some training performance by Gordon Elliott, considering the Authorized gelding was only having the third ever run of his life.
Said Elliott: “This is a dream come true, we have been hitting the cross bar all week. I feel sorry for Bryan Cooper, but am delighted for Davy, because he is always very unlucky when he rides for me. I am very lucky to be training for amazing owners.
“I was nervous early because he was a bit keen. He will probably go to Punchestown now, I will have a chat with Michael and Eddie (O'Leary).
“This was only his third ever start over hurdles and I think there is still improvement to come.”
Commented Russell: “I spoke to Gordon last night and he told me he (Tiger Roll) was coming on and should run well.
“We don't normally do this, but we gave him a pop over a couple this morning to keep his mind right and it looks as if it worked.
“We had a nice clear passage through the race. Life will throw plenty of things at you and there has been a lot worse thrown at other people (getting fired by Gigginstown). What happened to me, that's just life.
“It's great to get a winner at Cheltenham and this is exactly where you want to be riding them.”
Noel Meade, who doesn't have the best of records at this meeting, and whose horses have been very much out of sorts of late, landed the Albert Bartlett Novices' Hurdle with 33-1 shot Very Wood, completing a double for Gigginstown.
Very Wood, who was almost withdrawn the previous day, after going lame with a stone bruise, was supposed to be better travelling right-handed, but, under the most magical of drives from Paul Carberry, scored in fine style.
Carberry, typically, was in no hurry, but produced Very Wood with impeccable timing in the straight to beat Deputy Dan and Dessie Hughes' Apache Jack.
Said Meade: “We pulled him out of his box in the morning and he could hardly put his hind leg on the ground.”
The course vet then rang Meade and informed him the horse had no chance of being sound in time and to take him out. Meade, however, decided to poultice Very Wood and declare anyway.
Reported Meade: “We took the shoe off and got stuck into it straight away. A bucket of pus came out, which was the best thing, and when we put the shoe back on today he was fine.”
Meade, saddling a fourth festival winner, over a particularly long period of time, continued: “It's hard to beat a winner here, everybody who trains jumping horses wants to win at Cheltenham. We dream about it from the start of the season.
“We came here with only two runners, which is unbelievable given that we felt, at the start of the season, we had out best team ever.
“But we got a bug six weeks ago, had to shut up shop for three weeks and it has been hard to take.”
Said Carberry: “He jumped super, is a big horse with a big stride and, I'd imagine, will be going over fences soon.
“That was the first time I have ridden him and he gave me the feel of a stayer, I was confident all the way round.”
Supporters of Briar Hill, with David Casey in the plate, instead of the injured Walsh, were entitled to be sick after the race.
Briar Hill was tracking the leaders when crashing out at the sixth last.
In his previous outing at Naas, Willie Mullins' charge had decisively beaten both Very Wood and Apache Jack, and that speaks for itself.
Tiger Roll and Very Wood were just two of six winners Ireland managed through the day.
Leading trainer for the meeting, Willie Mullins, pushed his total for the week to four when Don Poli, partnered by Mikey Fogarty, took the Martin Pipe Conditional Jockeys' Handicap Hurdle.
Davy Russell added to his gains on Lord Windermere and Tiger Roll by completing a spectacular treble in the Johnny Henderson Grand Annual Chase, driving Savello to victory, while Tammys Hill won the Foxhunters for Northern Ireland trainer, Liam Lennon.
Gigginstown, after a quiet three days, struck for four winners with Tiger Roll, Very Wood, Don Poli and Savello and two of them were ridden by Russell.
For the powerful Russell it really was a day of days and, perhaps, Michael O'Leary was left wondering just why he removed him in the first place.
Ireland's final tally for the week was a more than satisfactory 12 winners.