Munich, Germany (My Sportsbook) - Germany's own Martin Kaymer fired a flawless, nine-under 63 on Friday to take the lead midway through the BMW International Open.

Kaymer, last year's Rookie of the Year on the European Tour, is through two rounds at 13-under 131 and owns a five-shot lead at Golfclub Munchen Eichenried.

Benn Barham shot a four-under 68 and is tied for second place with Francois Delamontagne, who carded a six-under 66 on Friday. The pair is knotted at eight-under 136.

Kaymer started off well with two birdies in his first three holes. It was his run of three birdies in his final four holes on the opening nine that got Kaymer into the lead on his own.

The German continued his fine form with back-to-back birdies at 10 and 11. Kaymer, armed with a two-shot lead, parred his next four holes, but once again went on a little run that padded his advantage.

Kaymer birdied the 16th hole, but found trouble at the par-three 17th. His tee ball landed in a bunker and he blasted out to eight feet. Kaymer calmly stroked in the par-saving putt, preserving his streak of bogey-free golf since his fifth hole on Thursday.

At the par-five closing hole, Kaymer drove into the fairway, avoiding the water. He knocked his second into the rough behind the green, then chipped to eight feet.

Kaymer converted the birdie putt to take his five-shot lead into the weekend.

"I hit a couple shots off line, but my putting was really good today," said Kaymer, who made the cut last week at the U.S. Open at Torrey Pines. "I hit a couple 15-, 20-footers that went in. So on one hand, it was a lucky round, because if I putt just normal, it would be like four- or five-under. But nine- under, it was pretty good."

Kaymer will be in search of his second European Tour title. He captured his maiden victory in January of this year at the Abu Dhabi Golf Championship after his Rookie of the Year campaign in 2007.

Kaymer delighted the home crowd for sure and the first two rounds were special. Kaymer played with fellow countryman and Hall of Famer Bernhard Langer.

"It's nice to play in your own country," said Kaymer, who currently sits 12th on this year's Order of Merit. "There was a lot of support yesterday and today already, and to play with Bernhard Langer was awesome. He didn't play as good as he played a couple weeks ago, that's for sure, but you can always see how good he is, if he needs it."

First-round co-leader Mardan Mamat (71), Tino Schuster (68), Henrik Stenson (68), Richard Finch (68) and Graeme Storm (69) share fourth place at seven- under 137.

Retief Goosen, Thomas Bjorn, David Howell, Thomas Levet and Paul Casey headline a group tied for ninth at minus-six.

Mamat's fellow first-round co-leaders did not fare as well as he did on Friday.

Rafa Echenique and Anton Haig both shot rounds of one-over 73 and are tied for 21st at minus-five, while Peter O'Malley struggled to a three-over 75 and fell into a share of 36th at three-under 141.

Defending champion Niclas Fasth managed an even-par 72 and is tied for 50th at minus-two. Langer, a five-time runner-up at the only event played on the European Tour in Germany that he never won, also shot a 72 and is in the group tied with Fasth.

The 36-hole cut fell at one-under 143. John Daly and the European Tour's Order of Merit leader, Miguel Angel Jimenez, who tied for sixth last week at Torrey Pines, both missed the weekend by a stroke.