Three mile champion One Man found the speed to claim the scalp of Viking Flagship and capture the £30,000 Peterborough Chase at Huntingdon yesterday. The grey completed an ideal dress rehearsal for his challenge to win a third King George VI Chase at Kempton by handing out a nine-length beating to the former two mile king. But One Man's first victory over two and a half miles since 1994 was tarnished by injury to Martha's Son, winner of last season's Queen Mother Champion Chase.

After jumping just four fences Tim Forster's charge was hastily pulled up by Rodney Farrant. He was later taken to the nearby Abbots Ripton Veterinary Hospital for X-rays on a suspected cracked pastern in his near-fore.

"The initial diagnosis is he may have cracked something like a pastern, as opposed to a tendon which he did last time, because he went so lame so quickly," said Forster.

One Man had been tracking The Last Fling when Martha's Son dropped out. But the Greystoke chaser took up the running when the leader blundered and unseated Richard Guest at the ninth, almost bringing down Viking Flagship.

Quickening down the back, he had still not shaken off Viking Flagship until out-jumping his rival at the second last to seal the race.

"It's sad about Martha's. You don't want that to happen to any horse. We came to find something out and have had to do it without him," said trainer Gordon Richards.

"But it's Kempton next stop and even if he'd been beaten that would still have been the target. What his target after that is, we'll have to see. He's not a Gold Cup horse anymore, though naturally his owner John Hales would have liked to win the race with the best rated chaser."

Winning rider Richard Dunwoody said: "He was really vibrant today. People knocked him when he was beaten by Strong Promise. But he ran a cracking race when not 100 per cent. He will go to Kempton with a great chance and I'm certainly looking forward to it."

Viking Flagship heads for the Tingle Creek Chase at Sandown, his trainer offering no excuses for his charge. Bookmakers William Hill reacted by issuing prices on next year's Queen Mother Champion Chase, installing Strong Promise, who beat One Man over this trip at Ascot last term, 5 to 2 favourite. But One Man, not certain to line up at Cheltenham at all, is a 9 to 2 chance with Viking Flagship behind Klairon Davis on 7 to 2.