Dun Doire (left) - huge improvement this season.

Tony Martin's charge started his winning run at Wetherby in November off a mark of 79 but his sixth win on the bounce off a 50lb higher rating appeared unlikely as he raced towards the rear of the field.

He still only had three stragglers behind at the top of the hill with three to jump and was 20 lengths adrift of the leaders.

But Ruby Walsh has few peers under such circumstances and he kept persevering on the 7-1 shot. Dun Doire responded with a rare finishing kick to collar Nicky Henderson's duo Juveigneur (16-1) and Irish Hussar (66-1) halfway up the run-in to land the spoils by two lengths and one and a quarter.

Model Son 14-1 was fourth.

"The bit of rain we got made all the difference," said Martin, whose previous Festival winner came with Xenophon in the Coral Cup three years ago.

"He has serious stamina and he does lack a bit of speed but the further he goes the better he is.

"It's everything to win at Cheltenham - it's like Wembley for the soccer players, it's magic. We were just lucky enough to have a horse good enough to aim for Cheltenham."

Explaining the exaggerated waiting tactics, Martin said: "He's just too slow to ride him any other way. If we raced him up there he wouldn't have got home with a puncture and it would have been good night for him.

"The original plan was the four-miler but after he won the Thyestes we decided to come here. He's an old-fashioned horse and the softer the ground he can gallop all day."

Martin added: "He's entered in the Irish National and the Betfred but it's too early to say - the ground might be too hard for him at Fairyhouse. We'll just give him a fortnight and see how he is.

"His progress has just been down to getting the trip and the ground right for him. In his early days he wasn't strong enough to gallop but he has just really started to progress.

"Hopefully fingers crossed he'll go for the Grand National next year - that's the road we want to be going down."

Walsh, who was completing a 55-1 double having won the Supreme Novices' Hurdle on Noland and is 4-9 with totesport to be top jockey at the meeting

The second-last was cordoned off as paramedics attended to Andrew Thornton, who took a heavy fall when A Glass In Thyne came down on the first circuit.

The jockey was stretchered off the course and he had an injury to his left forearm and was due to get an X-ray on his way home.