Sam Waley-Cohen became the first amateur rider to win the Totesport Gold Cup for 30 years on the final day of the Cheltenham Festival, taking an epic renewal of the season’s most important jump race on his father Robert’s Long Run.

It was a thrilling race and, despite a couple of jumping mistakes on the first circuit, 28-year-old Waley-Cohen powered home to win by seven lengths from previous champions Denman and Kauto Star.

It was a first victory in the race for trainer Nicky Henderson, and will go some way to make up for the disappointment of having to withdraw his Champion Hurdle winner Binocular from this year’s race because of a positive test for a banned substance.

Long Run was sent off the 7-2 favourite for the Gold Cup on the back of his defeat of Kauto Star in the King George VI Chase at Kempton. But two previous outings at Cheltenham had proved fruitless, and there was doubt about the quality of his jumping under pressure.

Midnight Chase and Tom Scudamore led the field for the first circuit. Long Run gave his jockey a couple of frights early on, but his jumping got better as Kauto Star and Ruby Walsh took up pole position and upped the pace on the second circuit. From the top of the hill it was all about Kauto Star, Denman, Long Run and last year’s victor Imperial Commander, but the latter dropped away quickly and Paddy Brennan pulled him up. Sam Waley-Cohen had to push Long Run a touch to get him to the leading pair, but he responded and came back on the bridle.

Kauto Star kicked off from round the final bend, but Denman matched him. A superb jump at the last pushed Long Run’s head in front and from there he motored up the hill to deafening cheers from the crowd. Denman passed Kauto Star for second, while What A Friend, owned by Sir Alex Ferguson and, like the two ahead of him, trained by Paul Nicholls, got to within a short-head of Kauto Star for fourth.

“This is a very emotional moment,” said Waley-Cohen. “The horse jumped awesomely and was very brave. I didn’t know whether I was coming or going at some of the fences. You go into them and throw everything at them – your heart, your soul and your guts.

“It’s a surreal moment – sometimes achieving your dreams is difficult to comprehend.”

Paul Nicholls emphasised that he was “mighty proud” of Denman and Kauto Star – at 11, the pair are five years older than Long Run.

“I wasn’t expecting very much today but you have to hand it to them, that was an awesome horse race,” he said.