Long Run, left, kept Kauto Star at bay to win the King George VI Chase
BBC Sport at Kempton Park
Brilliant young steeplechaser Long Run thwarted Kauto Star's bid to create racing history as he trounced his rivals to win the King George VI Chase at Kempton.
Kauto Star, being ridden for the first time in a race by 15-time champion jockey Tony McCoy, was seeking an unprecedented fifth consecutive victory in the three-mile contest, but had to settle for third.
Trainer Nicky Henderson, claiming his fifth win of the day, sealed a one-two as Long Run beat stablemate Riverside Theatre by 12 lengths, with the four-time King George winner a further seven lengths adrift.
Amateur jockey Sam Waley-Cohen produced a faultless ride on 9-2 second favourite Long Run, who is owned by his father Robert.
"Long Run is a phenomenal horse and I'm so pleased he's shown people what he is capable of," said the 28-year-old Sam Waley-Cohen.
"He walked through the first but the thing we wanted to do was to get him to jump.
"It was a change of tactics to just go big and bold, and a couple of times I wasn't sure if I would get to the other side, but we had to take the sword to the king."
Kauto Star trainer Paul Nicholls said: "Sometimes when you watch him, you know he's going to win but I never thought that today.
"I was never really happy at any stage. The mistake cost him second but he has done incredibly well to even come here five times.
"He just looked like he had lost half a yard around here at the age of 11.
Sam Waley-Cohen enjoyed a superb ride on Long Run
"He's come back safe and sound, that's the main thing."
A bumper crowd had gathered for the rescheduled big race, which had been postponed from Boxing Day after snow hit the Surrey track.
Thousands had come to salute dual Cheltenham Gold Cup winner Kauto Star, considered by many to be the greatest steeplechaser of the last 40 years, and he was sent off odds-on favourite.
A fifth King George in a row would have surpassed the galloping grey Desert Orchid, who won four times in a five-year period.
But it was time for a new champion as Long Run, who only officially had his sixth birthday on New Year's Day, proved too good on the day for the 11-year-old Kauto Star.
Nacarat had made the early running, but the French-bred Long Run and Kauto Star were always in close proximity.
The reigning champion looked to be travelling well but when Waley-Cohen asked his horse to accelerate, BBC Sports Personality of the Year McCoy had to push the 21-time winner along.
A mistake by Kauto Star at the penultimate fence sealed his fate, and the foot-perfect Long Run surged to the line for a convincing victory.
McCoy had entered the race as the man of the moment after a year in which he won the Grand National for the first time on Don't Push It.
Last Saturday he completed the full house of Grand Nationals with a Welsh National win on Synchronised.
He went into the King George on the back of three victories on the day, including the Christmas Hurdle on Binocular.
But the golden run came to an end for the Northern Irishman, who has ridden more than 3,000 winners in a record-breaking career.
It was the third time he has been beaten in his first ride on a Gold Cup winner.
McCoy was second on Best Mate in the 2001 King George before winning a year later, and was unseated when riding Denman last year.
Meanwhile, Binocular, ridden by McCoy, was the convincing winner of a frenetic Christmas Hurdle at Kempton after an impeccable jumping display in the sixth race of the day, meaning he will take all the beating at Cheltenham in March.
"He's getting there," said McCoy. "I still think it was a little bit below his Cheltenham performance last year but he's improving all the time."
McCoy enjoyed a total of three victories at Kempton, winning the Juvenile Hurdle on Kazzene, before riding Ski Sunday to victory ahead of 3-1 favourite Skint in the Handicap Hurdle.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.