Four days after the biggest win of his life, Miguel Angel Jimenez pulled out of the Wales Open at Celtic Manor after 11 holes today.

Jimenez, whose victory in the PGA Championship at Wentworth took him top of the European Order of Merit and made him an almost certain starter in September's Ryder Cup, decided not to aggravate a right knee problem.

He was eight-over par and joint last when he told an official and his playing partners Phillip Price and defending champion Richard Sterne he was withdrawing.

"I've had treatment the last two afternoons," said the Spaniard, who hopes to be back to full fitness for the US Open in two weeks' time.

"It's not so much hitting the shots, it's more when I am walking. I feel it getting weak and there's no point going on. It's just going to get worse and worse if I do."

Jimenez had a double-bogey six at his fourth hole on the day the course which will stage the 2010 Ryder Cup was unveiled, turned in 40 and then started his second nine holes with two more double-bogeys.