South African Charl Schwartrzel joined compatriot Anton Haig at the top of the leaderboard midway through the second round at the 2.5-million-dollar Qatar Masters here on Friday.
Schwartzel, who was on two-under at the end of the first round, picked up five shots in a flawless round of 67 for an aggregate of seven-under-par 137.
Haig, who was in joint lead with Lee Westwood after the end of Thursday's first round, suffered a double bogey five on the third hole, but shot four birdies after that and also on 137 with eight holes remaining to be played.
England's David Howell and Sweden's Noren Alexander shot 68 and 69 respectively to share second spot on six under after completing their second round.
Schwartzel was surprised by the cold conditions n Qatar.
"I wasn't expecting it. Like this morning, I had four layers of clothing on," said Schwartzel. "It was cold, but you have to cope with it."
Meanwhile, Westwood was having a rough time on the course after his fluent 67 on Thursday.
Westwood, who has won 18 European Tour events, shot a bogey on the fifth hole to be four under having played six holes on Friday.