Irish raider Solwhit benefited from the absence of the injured four-time winner Big Buck's to win the World Hurdle at the Cheltenham Festival.

Solwhit was given a brilliant ride by Paul Carberry, especially as the jockey had been in doubt on race morning after taking a heavy fall on Wednesday.

However, the Grand National winning jockey produced the 17-2 chance - trained by Charles Byrnes - to take the honours ahead of 40-1 outsider Celestial Halo, trained by Big Buck's trainer Paul Nicholls.

"It was touch and go whether I rode this morning," said Carberry, who provoked the thousands of Irish racegoers into wild cheers when he whirled the Irish flag over his head as he entered the winners' enclosure.

"I got a jab in the arm after a bad bang on my shoulder which damaged ligaments.

Earlier Ryanair boss Michael O'Leary was denied the chance to recoup the money that went into sponsoring the STG265,000 ($A387,568) Ryanair Chase as his hot 2-1 favourite First Lieutenant had to make do with second behind Cue Card, ridden by Joe Tizzard and trained by his father Colin.

"It is fantastic as a dad for Joe to win," Tizzard said.

"It is not easy having your son riding all the time as when things do not go well you get accused of nepotism but he was fantastic today."

"I was nervous before the race but Cue Card was so relaxed. It was a real professional effort and I am chuffed to bits with him," said Joe, who was riding his and his father's second winner of the meeting.

First Lieutenant, who had been originally entered for Friday's Gold Cup had to have a change of jockey after regular rider Davy Russell was taken to hospital with a collapsed lung.

Russell's replacement Bryan Cooper while unsuccessful in the Ryanair had tasted success earlier on the card when he steered home 20-1 Irish outsider Benefficient in the Novices Chase.

"I have been dreaming of this for so long, it is a shock," Cooper said.

"It gives me shivers up my spine."

There was another long-priced winner in the Pertemps Final Hurdle as 25-1 shot Holywell won for the ever popular England-based Irish trainer Jonjo O'Neill.