England's David Lynn stormed to a one-shot lead at the halfway stage of the US$1.8-million Volvo China Open on Friday, playing through the pain after quick surgery in a back room of the clubhouse.

The 32-year-old, seeking his second European Tour title since turning professional a decade ago, went under the knife on Thursday after his opening four-under-par 68 at Beijing's Honghua International Golf Club.

He needed further surgery just before beginning his second round to remove a painful lesion in his groin that has been hindering his swing and affecting his putting stance all week.

"I played my round (Thursday) and the doctor turned round and said 'Right, we need to cut it out.' And I went into a little room in the clubhouse and he got his scalpel out - no anaesthetic - and he just cut away," said Lynn.

"And actually, just before I went out this morning the doctor cut away another little bit. It's quite funny that I'm on the slab just before I get on the tee!"

Despite the inconvenience, he shot a five-under-par 67 with nine birdies to move to nine-under for the co-sanctioned Asian Tour and European Tour event.

Zimbabwean Marc Cayeux, Thailand's Prayad Marksaeng and Jose-Filipe Lima of Spain were a shot further back at eight-under par.

Defending champion Paul Casey followed up his opening 71 around the challenging par-72 7,203-yard Nick Faldo-designed course with a 68, moving to five-under for the tournament to remain in striking distance of the leaders.

Sweden's Henrik Stenson, the pre-tournament favorite, fought back after his disappointing first-round 73 with a 68, which included eight birdies, to lie six shots off the pace.

It could have been so much better but the long-hitting 30-year-old, ranked 13th in the world, found the water twice on the 429-yard sixth hole - his 15th - to record a quadruple bogey.

Taking advantage of the relatively benign conditions and starting from the 10th, Lynn, winner of the 2004 KLM Open, got off to a blazing start with three birdies in his first five holes.

He dropped a shot on the signature 422-yard 15th but picked up two birdies over the next two holes, only to give the shots back with a double bogey on the 18th after finding the water.

Coming home, the lanky Englishman recorded four birdies in succession beginning at the second but finished with a bogey on the 446-yard ninth after his ball plugged in a greenside bunker.

"Tee to green, I won't say I feel like I'm at my best. My putting has been nice and if I can keep that going it'll be good. You never know what's going to happen," he said.

"I get a buzz leading a tournament and will try to keep it going," said Lynn, who has had three top-10 finishes in seven tournaments this season.

"I feel like I'm on the verge of knocking one off soon if I can play a bit better from tee to green."

(China Daily April 15, 2006)