Parrott, the world No 2, a beaten finalist in this tournament in 1988 and 1989, said: 'I've played snooker constantly since August and I need a break. I came to Doncaster not feeling I was going to win. If I was a horse I'd be called 'over the top'. I certainly won't be going in the practice room for a few days.'
Parrott started impressively, winning the first two frames, and seemed on course to avenge a 10-5 defeat in last month's Belgium Masters final in Antwerp. But errors crept into his game and by the end of the opening session Wattana led 6-2 after breaks of 41, 65, 38, 73 and 43. He extended his frame-winning sequence to seven when play resumed with another half-century. Although Parrott recorded an 81, the best break of the match, his recovery was ended soon after.
Wattana next meets Stephen Hendry or Alan McManus. His victory means that he and not Parrott is now the favourite to win the world series. Parrott began the day with a two-point lead after events in Peking, Motherwell and Antwerp, but a place in Saturday's final would guarantee Wattana the title.
WORLD MATCHPLAY Quarter-final (Doncaster): J Wattana (Thai) bt J Parrott (Eng) 9-3. Frame scores (Wattana first): 9-80, 42-78, 60-25, 74-9, 66-26, 93-6, 79-30, 49-12, 76-0, 25-89, 68-30, 59-43.