Kauto Star created history with a fifth King George VI Chase victory in a perfect performance at Kempton Park.
The ever-popular 11-year-old, ridden by Ruby Walsh, won the race on four successive occasions from 2006 before being beaten by Long Run last season.
But the two-time Cheltenham Gold Cup champion gained revenge on this year's Gold Cup winner in spectacular style.
The 3-1 chance jumped superbly to finish a length and a quarter ahead of the evens favourite Long Run.
Kauto Star was never far away from the front of the field, as he had been when he beat Long Run to win the Betfair Chase at Haydock in November and led with a circuit to go.
He quickened the pace heading down the back straight and his jumping kept him at the head of affairs as Long Run had some less than comfortable moments with his jumping under Sam Waley-Cohen.
Although Long Run stayed on strongly in the home straight, he was unable to catch up on the winner.
The victory is a remarkable turn of affairs for the Paul Nicholls-trained horse, whose career looked in doubt at the start of the season following the defeats by Long Run in the King George and the Gold Cup before pulling up at Punchestown in May.
There were many who believed that his Nicky Henderson-trained rival would progress from the Haydock defeat but his odds to retain his Gold Cup title have been eased to 3-1 while Kauto Star is now around 9-2 to win the race for a third time.
Nicholls said: "He's just awesome and I knew we had him in serious order. I don't know why he wasn't quite right last year.
"It was a massive plus having Ruby here today and it's just unbelievable. It's amazing. He's just the best.
"If he gets to Cheltenham in that form he'll be the one to beat [in the Gold Cup]."