By Matt Smith
ABU DHABI (Reuters) - Martin Kaymer vowed to persist with an aggressive approach after claiming a one-stroke lead at the halfway stage of the Abu Dhabi HSBC Golf Championship following a flawless second round 67 on Friday.
The 30-year-old, who rattled in 10 birdies for an opening day 64, is a three-times winner of the tournament and will start Saturday on 13-under, a stroke clear of Belgian outsider Thomas Pieters and two ahead of world number one Rory McIlroy.
The German has proved an able front runner in the past, winning last year's U.S. Open by eight shots.
"At the U.S. Open I really played my own game, I didn't compare myself to the other players, I was trying to see how low I could play and I stayed aggressive," Kaymer told reporters.
"You're playing well, so you need to continue and not play more defensive."
Kaymer's triumph in North Carolina last June ended a three-year title drought and lifted him back into the world's top 20.
He has not had a single-digit ranking since May 2012, but appears to be approaching the form that once made him among the golf's very best.
Starting one stroke clear of Pieters on eight under, the world number 12 picked up shots at his third, fourth and ninth holes.
Kaymer chipped in from the bunker at the next to reach 12 under, but then found sure-fire birdie chances difficult to create, missing from 15 feet or more on the next six holes.
The two-times major winner sunk an eight-foot putt on his 17th for a fifth birdie and did not drop a shot all day.
"I made 80-85 percent of the realistic birdie chances," added Kaymer.
(editing by Justin Palmer)