Trainer Nicky Henderson capped an incredible day at the Cheltenham Festival by winning the Sportingbet.com Queen Mother Champion Chase with Finian’s Rainbow.

It was his third success of the afternoon, and he later managed a fourth with Une Artiste in the Fred Winter Juvenile Handicap Hurdle.

But Finian’s Rainbow’s victory was somewhat spoiled by heated discussion after the race as to whether the runner-up, last year’s winner and the hot favourite Sizing Europe, would have won if his jockey had realised earlier that the final fence was cordoned off. He had to veer sharply right to avoid it and lost ground.

Jockey Richard Johnson and Wishfull Thinking had taken a bad fall at the fence on the first circuit – cannoning under the rail and into a photographer – and officials decided to omit it as Johnson and the photographer were lying injured behind it.

Sizing Europe’s jockey Andrew Lynch appeared to be going to jump it, before changing his mind and swinging sharply away, while Barry Geraghty on Finian’s Rainbow was on their far side and could maintain their line and momentum. The two horses battled up the straight, but Finian’s Rainbow held off Sizing Europe by more than a length at the post.

“I just hope everyone is alright, that is seriously important,” said Henderson. “It was a great race and it was a pity they did not have the fence there as it was a tremendous race between two great chasers.”

Sizing Europe’s trainer Henry de Bromhead said: “We haven’t discussed it yet but Andrew [Lynch] said the last lost him the race.”

Earlier, Henderson took the Neptune Investment Management Novices’ Hurdle with the impressive Simonsig. That win meant he broke Fulke Walwyn’s longstanding record as the most successful trainer at the Festival with 41 victories.

It was swiftly followed by another, secured by Bobs Worth in the RSA Chase, in which the favourite Grands Crus ran disappointingly in fourth, 18 lengths behind the winner.

Welsh trainer Rebecca Curtis got off the Cheltenham mark in the first, the National Hunt Chase, with Teaforthree. And Willie Mullins continued his fine record in the Weatherbys Champion Bumper, winning with the 16-1 Champagne Fever, ridden by his son Patrick.

Donald McCain took the competitive Coral Cup comfortably with Son Of Flicka, a second winner of the week for him and jockey Jason Maguire.