Lee Westwood overcame a wasp sting to maintain his bid for a second European Order of Merit title today.

Westwood opened the Portugal Masters at Oceanico Victoria in sunny Vilamoura with a six under par 66 to be only one behind early clubhouse leaders Alastair Forsyth and Charl Schwartzel.

But the Ryder Cup star's playing partner Colin Montgomerie - a lowly 103rd on the money list and 255th in the world - had to be content with "only" a 68 after also going to the turn in 32.

Westwood was stung on the long 17th, his eighth, and lifted his right trouser leg to reveal a big red mark.

"It only hurts when I put my foot down. It's going to be one long hop round the front nine," he said.

However, that did not stop him adding further birdies at the second, fifth and sixth before driving into the rough cost him a bogey on the next.

"I'm lucky I'm not allergic to stings," he added afterwards.

"I saw it clinging on while it was stinging me, but I'm a big hard strong lad!"

Westwood is fourth on the Order of Merit and with a chance to go top this weekend, but current leader Rory McIlroy, one of the later starters, waited only until the second hole for his first birdie.

Forsyth, who with David Drysdale helped Scotland qualify for the World Cup last month, birdied the last three holes to set the target of 65.

That completed a back nine 31, while Schwartzel's four birdies in his last seven holes brought the South African level.

Padraig Harrington was in the water for bogeys at both the 17th and 18th, but felt his putting let him down more than anything in his 69.

The Dubliner had returned to the putter which won him his three majors, but felt he did not make the necessary adjustment to it being just under an inch longer.

"I was just not familiar enough with it and caught the ground," he said.

"I just fancied a change."

Ben Curtis, another former Open champion, is over from the States this week and he matched Montgomerie's 68, while Darren Clarke was another to score 69.