Sam Waley-Cohen became the first amateur jockey to win a Grade One National Hunt race since Jim Wilson in 1981 when he rode his father Robert's horse Long Run to victory in the King George V Chase at Kempton on Saturday.

Kauto Star, ridden by AP McCoy, had been expected to break the record with a fifth successive triumph in the race, but Waley-Cohen swept to victory as Long Run outpaced the champion over the final circuit.

Waley-Cohen said that he had no plans to turn professional despite the triumph, preferring instead to concentrate on his dentistry business.

He also confirmed that he would be challenging for the Gold Cup at Cheltenham, though he has no plans to enter either Grand National.

But he is hopeful of another triumph. "The Gold Cup is another race on another day. Hopefully lady luck is smiling on us and then we could have a good chance."

Having produced the race of his life, Long Run will need to retain the superb form he displayed at Kempton if he is to repeat the feat at Cheltenham in March, where his jumping let him down in the Sun Alliance chase last year.

Saturday's victory was owed in large measure to Long Run's improvement in this area, which Waley-Cohen and trainer Nicky Henderson have been working on since his first run of the season in October at Cheltenham, in which he finished third.

It paid off as he produced a faultless display over the Kempton fences.

"He's improved enormously and was very fast and fluid. That made the difference.

"We have been working to make sure that he adapts his style of racing to the UK." Long Run was bred and initially trained in France.

Waley-Cohen timed Long Run's surge to perfection on Saturday, after Nacarat had led for much of the race. "I was comfortable sitting behind, though for a second, I thought he might gallop to the line. Once we turned into the home straight we felt we had his measure."

The jockey says that the enormity of his achievement is still to sink in completely, particularly given his status as an amateur.

"It's obviously great to win a race of this class. Given that no amateur has done it for such a long time makes you realise how difficult it is. It is also a great honour to ride against a horse like Kauto, and with a jockey like AP McCoy. That makes it doubly exciting."