Diamond Harry posts a sparkling display

Williams' well-backed gelding foils top-weight Denman's brave bid for an unprecedented third Hennessy Gold Cup

If it was a failure, it was a gallant and glorious one. Denman did not win an unprecedented third Hennessy Gold Cup here yesterday but by looking as if he might until the 20th of 21 fences he gave the frozen faithful in the grandstands an emotion-wrenching winter heartwarmer. They responded by cheering the big gelding and his rider, Sam Thomas, throughout; in flight over the birch and ditches, in his fight through the closing stages and in his unbowed might as he returned to the spot reserved for the third-place finisher.

They also gave a rousing reception to the winner of this classiest staying handicap chase of the season, Diamond Harry, who signalled his emerging talent as he took advantage of his light weight. Carrying 10st to Denman's 11st 12lb, the seven-year-old was always among the leaders and, with Daryl Jacob in the saddle for the first time, put in an exhibition round of jumping.

A relentless pace was set for more than a circuit by Hey Big Spender on testing ground suited those who were able to maintain a rhythm, none more so than Diamond Harry and Denman. The pair came into the home straight together and settled to the battle. A slight mistake by Diamond Harry four out handed the advantage to Denman, but Diamond Harry, a well-backed 6-1 shot, regained his equilibrium and the two rose to the third last, the final open ditch, as one. But it was clear the young pretender, the star of Nick and Jane Williams's small Devon string, had the old warrior's measure and a mistake from Denman at the penultimate fence settled the issue.

Another lightweight, Burton Port, recovered from a blunder at the cross fence well enough to stay on for second, a length and a quarter adrift. It was 14 lengths back to Denman, who held his own Paul Nicholls stablemate The Tother One at bay by half a length, with Niche Market fifth.

Diamond Harry, in the colours of Paul and Janet Duffy, was running in a chase for only the fourth time; he was a talented staying hurdler early last season but after being firmly put in his place by the king of that division, Big Buck's, was diverted to fences.

"The horse has changed physicallya lot in the last six months," said Nick Williams, who combines training with an accountancy business, "and he has a good record here, so I thought this was the race for him.

"Coming into the straight I could see Daryl hadn't moved. From three out I would have been astounded if anything had got past him."

Jacob was just as confident, though quick to acknowledge Denman's effort. He said: "If we were going to beat him it had to be today, but he was still right there with me at the second-last. But I'd sat on mine during the week, and I'd told Nick I'd never ride one like him again.

"He gave me the same feel today; he jumped, he travelled, he did everything I asked him to. And he's a young horse, and still unexposed, still growing into his frame. The Gold Cup is a way off – he was getting all that weight today – but we can dream."

Lightweights in handicaps are by definition horses who have not achieved as much as those rated above them, but this is a contest that can spotlight upwardly mobile types who can progress to mixing it with the best when the playing field is level.

Diamond Harry may be given his chance in the Grade One Lexus Chase at Leopardstown after Christmas. Bookmakers are divided over his Cheltenham Gold Cup chances, though, rated between 8-1 and 14-1.

Denman, who won the Hennessy in 2007 and last year under the same welter burden and started 4-1 favourite yesterday, was trying to achieve what even Arkle could not; the peerless one went down by half a length to Stalbridge Colonist, conceding 35lb, when trying to win his third edition back in 1966. The 10-year-old will not run again until the Gold Cup.

"He had a hard race," said Thomas. "But then, he always does, because he always gives it everything he's got. He'll sleep well tonight."

Of the two reigning champions to make their seasonal debuts here, Big Buck's return to action went smoothlyin the Long Distance Hurdle, but a ring-rusty Binocular could finish only third to the Donald McCain-trained Peddlers Cross in the Fighting Fifth Hurdle as he began the defence of his Champion Hurdle crown.