Soren Hansen takes over lead - Mercedes-Benz Championship 2007

Westwood, who was four ahead of Hansen overnight, maintained that advantage by chipping in for an eagle on the long seventh. But the former European number one's round disintegrated as the wind got up on the back nine.

After finding water at the 18th to card his fourth bogey on the inward half, the Englishman's 73 left him a stroke behind Hansen.

Event promoter Bernhard Langer and British pair Simon Dyson and Simon Khan shared third spot, four strokes off the pace.

Hansen, with one third-place finish and two seconds recently, stood out in his threesome with former European Ryder Cup captain Langer and twice major champion John Daly.

"Yesterday I made it look easy but today I needed to make some good up and downs," the Dane told reporters as he chased his second European Tour title. "The way I've been playing for the last three months I've got to be rewarded.

"My putting is so much better and my short game is that little bit sharper, they're ingredients for that big package. Lee Westwood in form, though, is always a dangerous man," said Hansen, who is 13th on the money list.

Westwood was unable to replicate his spectacular opening 61.

"Your expectations are high but you don't generally follow up a 61 with anything better," said the Englishman.

"I missed too many fairways but I didn't get much out of my round, the wind got up and the greens firmed up. I also had a bad night, I was all stuffed up (with a cold) and my balance felt a bit upset."

Langer, 50, is looking to become the tour's oldest winner and would have been closer to the lead but for two poor late tee-shots as he returned a 68.

Dyson, trying to edge out fellow Briton Nick Dougherty for a place in the Seve Trophy later this month, posted a 71 while late finisher Khan bogeyed the 18th in gathering gloom for a 70.

Daly was a further stroke back on 138 after another 71.