Sam Waley-Cohen came within two and a half lengths of becoming the first amateur jockey to win both the Cheltenham Gold Cup and Grand National in the same year as Oscar Time finished runner-up at Aintree.
Crossing the line behind Ballabrigs, Waley-Cohen said that it was still surreal to have achieved all he has this season, having also won the King George VI Chase at Kempton in January on Long Run.
"The overriding feeling is one of disbelief at what a wonderful season it has been. It is more than you can dream of achieving.
"As an amateur, you don't expect to win any of these races so to win two is fantastic. But to have had such a great run, it is frustrating to not quite get to terms with Ballabrigs."
Following an assured ride, Oscar Time started to cut through the field in the closing stages and was gaining ground on Jason Maguire's Ballabrigs as they cleared the final hurdle, only to come an agonising second.
The race was marred by the death of two horses, Ornais and Dooneys Gate, which forced two fences to be missed on the second circuit of the course.
Critics have said that the Grand National is cruel on the horses, with some comparing it to bullfighting in Spain, but Waley-Cohen dismissed such claims.
"It's always tragic when a horse dies during a race, whether it's the National or any other race.
"Cruel is 100 per cent the wrong word, because when they are galloping they are doing so with real enjoyment and enthusiasm."
Waley-Cohen, 28, who runs a string of dental practitioners, explained the secret of his success this year.
"The number one trick is to be on the right horse. You need a lot of luck and it's a big team effort. There are a lot of people behind the horse. You're the most visible person in that big team behind it."