Greg Owen, who briefly led the British Open championship earlier this year, produced a brilliant scoring burst to claim a share of the lead in the German Masters in Cologne yesterday.

Owen fired eight birdies and just one bogey in a seven under par 65, to join Sweden's Henrik Nystrom in the lead at Gut Larchenhof.

Argentina's Ricardo Gonzalez, seeking back-to-back European Tour victories after his maiden win in Switzerland last month, was one shot behind after a 66, along with Australian John Senden.

No fewer than 12 players were a shot further back on five under, including England's Ian Poulter, and tournament co-promoter Bernhard Langer, the German looking forward to writing himself a handsome prize money cheque on Sunday.

Ireland's best performer on the day was Darren Clarke, who shot a 68. Padraig Harrington, who professed himself delighted with the results of laser eye surgery he underwent last week, carded a 70, as did Paul McGinley.

Clarke looked set to challenge the leaders when he had four successive birdies from the third and was five under par after 10 holes.

But the Ulsterman failed to birdie either of the par fives on the back nine and bogeyed the 14th and was in no mood to talk about his 68 afterwards.

Owen started slowly with six straight pars as he felt the ongoing effects of a long-standing back problem caused by his 6ft 4in frame - a problem he hopes to rectify by working out with a martial arts expert this winter.

But he came to life from the seventh, carding four straight birdies and six in seven holes, only a lip-out on the 11th preventing him from making it seven in a row.

"It was fantastic," said the 29-year-old, a member of Barry Hearn's Matchroom stable who receives advice from six-time world snooker champion Steve Davis.

"The putts seemed to drop for me today and I kept hitting it exactly where I wanted. The longest birdie putt I had was from 15ft and it was a shame about three-putting the 17th.

"Leading the Open was a hell of an experience and one I'm never going to forget. But it took me about a month to come down from that and when I played in the Scottish PGA I was all over the place.

"I'm looking forward to a break over the winter and counting down the events, which is not a good thing to do. But I'm going to work hard over the fitness this winter with Ron Cuthbert, who is a martial arts expert, and hopefully I'll reap the rewards next year.

"I've had the back problem for about 10 years but it's something I put up with. It's not holding me back, but maybe my general fitness is. By about the 15th hole I feel drained and was counting the holes in."

Co-leaders Owen and Nystrom are both seeking their first tour wins and it could be the Swede's lucky week after he admitted to having his share of good fortune.

After a wayward drive on the second his attempted recovery from behind a tree ballooned straight up in the air and left him 45 yards short of the green, from where his pitch flew straight into the hole without bouncing for a birdie.

And his final birdie of the day on the 15th came after he found his ball in the rough only 30 seconds inside the five-minute time limit. "One of the other caddies found it so I owe him a couple of beers," said Nystrom, who is 121st on the Order of merit and needs to move into the top 115 to retain his card at the end of the season.

"I got a couple of breaks but I've been hitting the ball well and really worked hard on my putting, changing the whole thing."

Colin Montgomerie, who missed the cut in the Lancome Trophy two weeks ago when he admitted he was not fully focused after the tragedy in America, had to settle for 70, four shots behind playing partner Gonzalez.

"Nothing much happened," the Scot said. "I started well but dropped a few shots.

"I had a week off last week, did a little bit of practice trying to get my game in shape for the big tournaments coming up but it's not quite happening."

The third member of the group, Ian Woosnam, went one better with a 69 and confirmed he would love to be Ryder Cup captain when the contest is staged in Wales in 2010.

"It's a long time but I don't mind waiting," said the former Masters champion who backed Celtic Manor's successful bid.

Jose Maria Olazabal matched Woosnam's 69, while John Daly bogeyed his closing hole to card a one under par 71. Playing partner Lee Westwood, who parted company from caddie Martin Gray earlier this week, bogeyed the last two holes to card a level par 72.