Smith and Kauto Star also landed The King George on Boxing Day
Owner Clive Smith has told of his "mighty relief" after Kauto Star justified his big reputation for a famous Gold Cup triumph at Cheltenham.
Before Friday's win, Kauto Star had only run once before at the undulating track, when suffering a crashing fall in the 2006 Champion Chase.
It led to some critics doubting whether the seven-year-old, who had taken his previous five races at different tracks and distances, would even complete the course.
"I'm mightily relieved and feel very privileged that we've won," Clive Smith told BBC Sport.
Jockey Ruby Walsh guided Kauto Star to a two-and-a-half length victory over Exotic Dancer, with the winner surviving a trademark last-fence scare to land a £1m bonus.
He had been backed into 5-4 favourite and is estimated to have left a £10m bill for bookmakers, who had previously been enjoying the upper hand over punters at the four-day Cheltenham meeting.
It is rare for a steeplechaser to have the speed for Grade One wins over two miles, plus the stamina to succeed at trips of more than three miles, a versatility that helped Desert Orchid become a racing favourite.
Kauto Star's season has seen him complete a rare treble of Tingle Creek Chase (2m, Sandown); King George VI Chase (3m, Kempton) and Cheltenham Gold Cup (3m 2.5f).
Trainer Paul Nicholls (r) celebrates with jockey Ruby Walsh after Kauto Star's win
But just as racing was lauding a new star, sobering news came from Uttoxeter on Saturday where ante-post Grand National favourite Nil Desperandum was put down after breaking a leg.
Earlier in the week another leading National contender, Little Brick - the subject of a £1m gamble from 100-1 to 12-1 for Aintree glory in April - died at the Festival.
Smith, who also owns former Grand National runner-up Royal Auclair, has also experienced such lows and sympathised with the teams behind both horses.
"Things have got to go right for you. We were very lucky to be there at Cheltenham," said the 56-year-old, who designs and builds pay-and-play golf courses.
"Last year, there were 11 fatalities at the Cheltenham Festival, and Kauto Star had a crashing fall in the Champion Chase.
"It was as bad a fall as anyone could have, and he got out with nothing wrong, which is remarkable. You need a lot of luck in racing."
More than a year before that, Kauto Star fell in the final stages of a race at Exeter.
Walsh remounted the horse, not realising he was injured, and Kauto Star was sidelined afterwards for 10 months.
That all seemed a long time ago on Friday as Smith, Walsh, trainer Nicholls and thousands of racegoers saluted a champion.