Tragedy struck at Cheltenham this afternoon as 2015 Grand National hero Many Clouds died just minutes after defeating Gold Cup favourite Thistlecrack in a pulsating finish to the Cotswold Chase.
Owned by Trevor Hemmings, the 8-1 chance trained by Oliver Sherwood was winning the race for a second time, having also claimed the recognised Gold Cup trial before his big Aintree win.
Thistlecrack made several jumping errors on his way around, but came back on the bridle for Tom Scudamore jumping the last.
The Colin Tizzard-trained King George winner went clear on the run in, but the gallant Many Clouds would not go away.
But having answered every call for jockey Leighton Aspell, Many Clouds, who got home by a head, collapsed after the winning post, being treated immediately by veterinary staff before his death was confirmed.
Sherwood said: "We've got to look forward and not look back. He's been the horse of a lifetime and I always said he would die for you and he's died for me and the team today doing what he does best.
"He wanted to win that race, he was beaten and then fought back in the last 50 yards to win.
"It's sad for Trevor and my team at Rhonehurst, I've been in the game 32 years and horses like that don't come along very often.
"You've got to enjoy it and it happens to us all, we all go one day. We've got to be philosophical and celebrate the Hennessy and National wins and that was almost a career-best performance.
"One thing I want now is for Thistlecrack to win the Gold Cup."
He added: "It's a tough game and a great leveller - I feel sorry for Leighton Aspell and everyone involved with the horse. Leighton was the only one who'd schooled and ridden him in a race, but life goes on.
"The public get to know the horses, especially horses that try for you, they appreciated what he had done and he captured your imagination, really.
"It was quite spine-chilling when it was announced, there was a huge clap and that nearly finished me off.
"I had two large vodka and tonics to relax me and I've not had a drink for two months.
"When Lisa (Kozak, travelling head girl) rang me to say he'd gone down, I was worried. Time will tell if it was a heart attack."
A sombre Tizzard said: "We were just beaten by the better horse on the day, two fantastic horses ran right to the line.
"Poor old Many Clouds. My initial thought when we got beat was that I was disappointed but it's as sad as can be, he was a lovely horse and he beat us on the day.
"We ran our race, we're not making any excuses - today, on winter ground, we were beaten by a better horse, no question.
"They had a battle and it's just a tragic end to the race. This is what happens in our sport occasionally and you've got to face up to it."
Un De Sceaux bagged another Grade One when running out a clear-cut winner of the rearranged Clarence House Chase.
After being frozen off at Ascot last weekend, the authorities moved quickly to save the race and its star turn did not let his backers down.
Special Tiara and Royal Regatta put the pace to the race early on, but the latter had soon cried enough and Un De Sceaux moved up to join Special Tiara at halfway.
Approaching the fourth-last Special Tiara held an advantage, but a flying leap by the Willie Mullins-trained 1-2 favourite saw him hit the front and he would not be headed again.
On the run to the second-last, Uxizandre and Top Gamble briefly threatened but Un De Sceaux had loads left, jumping the last two in fine style to power clear for a five-length win from Uxizandre, who ran a huge race in second.
Mullins said: "He was very good. He jumped very big and fresh late on, which shows how well he is, but then I started to wonder if he'd have enough left for the finish.
"To be able to do that after coming back to Ireland and going to England again is very impressive.
"As for the Festival and which race, I'll have to chat to the owners but at this stage the Ryanair is possibly his race."