Bobs Worth provided Nicky Henderson with a second Betfred Cheltenham Gold Cup in three years under Barry Geraghty.
In maintaining his unbeaten record at the track, Bobs Worth, the 11-4 favourite, outstayed Tony McCoy and Sir Des Champs up the Cheltenham hill.
Long Run, Henderson’s winner from 2011, attempted to make all for his amateur jockey Sam Waley-Cohen but faded into third.
Silviniaco Conti was a faller at the third-last when still going well in the hands of Ruby Walsh.
Bobs Worth crept quietly into contention under Geraghty but there were still five in with a realistic chance coming down the hill.
The Giant Bolster, last year’s runner-up, was clinging on to the coat tails of the leaders but a slow jump at the second-last cost him his chance of glory.
When Bobs Worth and Sir Des Champs passed Long Run it was left to the two new kids on the block to fight out the finish and although Bobs Worth went clear, he began to idle on the run-in.
For a few strides it looked as if McCoy, a late replacement for the injured Davy Russell, would galvanise Willie Mullins’ charge, but he could not get back on terms and went down by seven lengths in the end with a further two back to Long Run.
Geraghty was tempered in his celebrations and quick to offer his thoughts for amateur rider JT McNamara, who suffered serious neck injuries in a fall on Thursday.
He said: “I’d love to be happier. All we can think about is John Thomas McNamara. We just hope and pray to God he’s OK.
“This is a brilliant, he is a gorgeous horse and he has a great attitude.
“He never travelled, he struggled on that ground, but he kept fighting.
“I knew three out I had five or six lengths to find, but I thought I had a good chance.
“He’s as game as a lion and he loves the job.”
Henderson, celebrating his 50th Festival winner, said: “It’s all a bit of a blur. You have to gather your thoughts. We’ve been at it a good few years.
“Both horses were fantastic and everybody has done a hell of a job. Bobs Worth hasn’t run since the Hennessy and Long Run hasn’t run since the King George, so it was all down to what we did at home and we did it as a team.
“I have to thank them all. They were brilliant."
Mullins said of Sir Des Champs: “It was a hell of a run.
“He didn’t appear to travel as well as he normally does and Tony was all the time niggling him.
“He jumped well enough and Tony was keen to be handy, he has lots of experience around here so I was happy enough to leave it to him.
“We were very happy in the run, he had every chance turning for home but he got outstayed in the end. I thought we had Long run’s measure but I didn’t look behind, maybe I should have done.
“I’d have rather it didn’t rain but the winner is by Bob Back so you wouldn’t have thought he’d like the ground either.
“He’s still a young horse and hopefully he’ll be back next year. I imagine he’ll go to Punchestown.”
Long Run’s owner Robert Waley-Cohen said: “I thought Sam judged the pace beautifully. I thought it was between him and Sir Des Champs turning in but Bobs Worth has come and sprinted past them both and I was thinking ’where did he come from’.
“I’d say that would be his last run of the season as he was trained to peak today and the Gold Cup is a very hard race.”
Walsh said of Paul Nicholls’ Silviniaco Conti: “Who knows what would have happened? The third-last is a long way from home.
“He jumped fine up to then but probably ran a bit keen and you have to jump to win.
“It was an even gallop. We could have gone a bit quicker maybe
“There’s no bother on him. He’ll probably go to Aintree or Punchestown.”