Lee Westwood and Robert Karlsson will have the Ryder Cup on their minds in the final round of the Deutsche Bank Players' Championship in Hamburg.

Karlsson holds a two-shot lead after shrugging off a weather delay of 95 minutes - and the theft of his ball marker - to card a 66 to lie 20 under par.

Westwood, seeking a third victory at Gut Kaden, fired a 67 to finish 18 under, two shots ahead of Ryder Cup captain Ian Woosnam and South African Charl Schwartzel.

World number five Retief Goosen, Scotland's Gary Orr and Italian Emanuele Canonica share fifth place on 15 under.

With 600,000 points on offer to the winner, victory on Sunday could be crucial to the leading duo's chances of qualifying for the European team at the K Club in September.

Karlsson could move as high as seventh in the standings while Westwood could reach as high as 12th.

Wales Open winner Karlsson had made a superb start to his third round with five birdies in the first seven holes but lost his momentum when play was suspended due to the threat of lightning with the last group on the 11th green.

When it resumed at 4.50pm local time both Karlsson and Woosnam's ball markers were missing and the pair had to estimate where they should be replaced before play could continue.

Karlsson had in fact been facing a relatively short birdie putt but eventually missed it and had to settle for par.

Ireland's Graeme McDowell gave himself an early birthday present with a third-round 65.

McDowell, who celebrates his 27th birthday tommorow, had set the early clubhouse target at 13 under par on another day of low scoring in Hamburg.

Eight shots off the lead overnight after rounds of 68 and 70, McDowell had earlier picked up five shots in the space of four holes at Gut Kaden this morning.

The Ulsterman, who led after the first round of the Open at Hoylake last week before fading to 61st, opened with two pars but then eagled the par-five third after a 3-wood approach to 15ft.

The 26-year-old from Portrush then birdied the fourth, parred the fifth and eagled the par-five sixth after another excellent 3-wood approach to make it five threes in a row.

His charge was halted by four pars in a row around the turn but birdies at the 11th and 15th completed an excellent round.

McDowell played with Ryder Cup captain Ian Woosnam in the first two rounds but admitted his chances of qualifying for the team at the K Club in September had all but disappeared.

"It's not nice for me to say the Ryder Cup has gone but I think it has because I haven't played well enough over the last couple of months," McDowell said.

"I have played a lot of golf over the past three months and I'm taking the next two weeks off because I need to recharge the batteries.

"I've been a little bit fried and haven't been firing on all cylinders so I really need to rest up and get myself right for the USPGA championship and look for a strong finish to the year and get myself back up the world rankings."