Three-time winner Martin Kaymer tightened his grip on the Abu Dhabi Championship on Friday, shooting a 5-under 67 to pull five strokes clear midway through the second round.

Two brilliant shots from the sand were the highlights for the overnight leader, who chipped in from a greenside bunker on his 10th hole and set up his fifth and last birdie with a 105-yard approach to eight feet from a fairway bunker on his 17th.

By following up a first-round 64 to lie on 13 under overall, Kaymer is 100 under par for his last 30 rounds on the National Course — where he won in 2008, '10 and '11.

Kaymer led by one shot overnight.

France's Alexander Levy is Kaymer's closest challenger on 8 under after shooting 70.