Watch a full replay of the RSA Chase plus Lydia Hislop's interview with a breathless Paul Nicholls.
Topofthegame broke his duck over fences on the biggest stage of all as he prevailed in a thrilling finish to the RSA Insurance Novices' Chase at Cheltenham.
Paul Nicholls has never made any secret of the regard in which he holds the giant seven-year-old, and the 10-time champion looks to have unearthed another genuine Gold Cup contender.
On his first start this season, Topofthegame (4-1) gave away 20 lengths at the start but still nearly beat subsequent Grade One winner Defi Du Seuill, then at Kempton over Christmas he lost out in a battle to La Bague Au Roi.
Watch a full replay of a gripping RSA Chase
Nicholls decided to keep him fresh and that paid dividends in a race which always turns into a war of attrition, and with fellow market leaders Santini and Delta Work coming clear with him at the second-last, he needed every ounce of effort.
A tactically astute Harry Cobden bided his time before seeing off Nicky Henderson's Santini by half a length.
Gordon Elliott will have at least been pleased to see the beaten favourite Delta Work run his race a length and three-quarters further back after poor displays from Apple's Jade and Battleoverdoyen.
Both Topofthegame and Santini were introduced into next year's Gold Cup betting at 8-1 by Paddy Power.
Nicholls told Racing TV: "I've always thought he is a very smart horse, he has not been the easiest to train but on his day he is good.
"I didn't say much to Harry on how to ride him, but just take your time whatever you do, and he gave him an absolute brilliant ride.
"He is nearly 18 hands and is just massive. I didn't want to go to the Reynoldstown with him and give him a hard race. I just had to get the balance right. We've always believed he is a serious horse.
A breathless Paul Nicholls on the massive Topfofthegame
"Today was the only day we have trained him for and next year it will be the Gold Cup.
"With Clan (Des Obeaux) and the other young horses we've got it is exciting to have them, but Rome wasn't built in a day and you have just got to let them develop.
"He is not unlike Denman and God willing he will stay sound he will be in the Gold Cup. Paul (Barber) is excited as he has him and Clan Des Obeaux."
He went on: "He jumped really well in behind them and it was a brave route to go as you don't want anything to go wrong. He still doesn't do a whole heap in front, but he does enough.
"It was shades of Denman really. We've always thought a lot of the horse, Harry learnt a lot from Kempton and the horse is learning all the time.
"He has got everything - he has got pace, he can jump and travel as well. He has been running in graded races and he was unlucky at Exeter the first time this season, but it was probably the making of him.
Harry Cobden says the winner is now a lot slicker over his fences
"He was travelling a bit too well at Kempton and got there too soon, but it doesn't matter. He might well be my new Denman, he is pretty much rated the same.
"Denman was a grinder, but this horse has got plenty of boot."
Henderson said of Santini, who has been plagued by a foot problem over the last week: "I think to get him here and run like that was a great effort by the team. It nearly came off.
"It (foot problem) wasn't ideal, of course it wasn't, but they've run to their Feltham (Kauto Star) form (from Kempton).
"It was an excellent race and Santini has jumped beautifully. I wish I'd had a cleaner run at it, but fair play to the winner - who I always said was going to be the one to beat."
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Elliott was pleased with the run of Delta Work.
He said: "I'm delighted. We're having a rough week and to get into the winner's enclosure felt like having a winner. We all know what this game is like and we have to keep our heads up and keep going.
"This horse jumped a bit novicey - he got close to a couple. It's a different speed over here.
"He didn't stop and galloped all the way to the line, so we're delighted."