Kauto Star's bid for a third Cheltenham Gold Cup victory was scuppered by a fall as Imperial Commander upset the favorite and former winner Denman to triumph for local trainer Nigel Twiston-Davies Friday. Billed as a showdown between Kauto Star and 2008 champion Denman, the race failed to follow the script after 8-11 favorite Kauto Star, who made a terrible mistake on the first circuit, fell four fences from the finish. Denman, ridden by Tony McCoy, was going strongly turning for home but had no answer to Imperial Commander, who produced an impressive display of jumping on rain-soaked ground to give jockey Paddy Brennan, 28, the biggest victory of his career. Imperial Commander (7-1) surged clear after the final fence and had seven lengths to spare at the line with Denman (4-1) second, as he was to Kauto Star last year, and last year's Grand National winner Mon Mome (50-1) third. Irishman Brennan celebrated after crossing the finishing line by turning towards the packed Grandstand and putting one finger to his lips. “Kauto Star and Denman...that's all I've heard about for the last three months,” Brennan told a news conference in explanation of his “silence” gesture. “It was never a two-horse race.” The winner had won the Ryanair Chase at last year's festival and was beaten only by a nose by Kauto Star when the pair clashed in a race at Haydock in November. “It's by far the best day of my life, I'll never ever forget this - I'm speechless,” Brennan told Channel Four television. “I would like to thank my boss. He is by far the best boss in racing. He produced the horses this week to the second, I just had to steer him.” It was a first Gold Cup success for Brennan and Twiston-Davies, who has twice won the Grand National - in 1998 with Earth Summit and four years later with Bindaree. Victory was consolation for Twiston-Davies, who is based just 19km from Cheltenham, after his Khyber Kim was beaten into second place in the Champion Hurdle Tuesday. “Absolutely superb. We saw Kauto was in trouble quite a long way out and were feeling quite confident,” the trainer said. “For us it's been very difficult as the third favorite, listening all about Kauto and Denman. For me Kauto was beaten when he fell, we always knew we were going to win.” Kauto Star, who had been bidding to join an illustrious group of four chasers to have won a hat trick of Gold Cups, returned unscathed from his fall. The hot favorite almost parted company with jockey Ruby Walsh after blundering at the eighth fence. Although the pair recovered, Kauto Star never regained momentum and he appeared to be struggling even before he fell. “It was a bad mistake, it knocked me out of position and obviously had an effect on him. He was never travelling after,” said Walsh. McCoy said Denman had run “in snatches”. “But he ran his heart out and didn't do anything wrong but just got beaten by a better horse on the day,” he said.