Paul Nicholls today hailed Kauto Star as a horse "at the top of his game" as he nears his 12th birthday.

The darling of the National Hunt game made history at Kempton Park as he recorded an unprecedented fifth win in the William Hill King George VI Chase, beating Long Run, five years his junior, by a length and a quarter.

In doing so, the Clive Smith-owned Kauto Star was following up an equally emotional win over the Gold Cup winner in the Betfair Chase at Haydock, and avenged his defeat at the hands of Nicky Henderson's charge in the King George last season.

Nicholls told BBC Radio 5 Live: "He was fantastic, right back to the top of his game. He's now won two races this year and both times has beaten the reigning champion Long Run. It was a fantastic day.

"He's had some great races, don't forget Kauto Star has had lots of battles with Denman and Imperial Commander, but he seems in the form of his life at the moment. Long Run is six and Kauto is 11 - it was just awesome by the horse."

Many had called for Kauto Star to be retired after he was pulled up at Punchestown in May, and Nicholls said: "Everyone is entitled to their opinion but really they should leave it to the people who know him best.

"The way he has been training this autumn has been second to none. He was below par last year, I don't know why, but he seems to be a horse at the top of his game at the age of 11.

"He's not sustained any injuries but he did have a hard fall in the Gold Cup two years ago. Whether it took him 12 months to get over, that might be the reason."