Danny Willett battled with fatigue before claiming a share of the clubhouse lead on day two of the inaugural Maybank Championship Malaysia on Friday.
Seeking back-to-back wins following his victory in the Dubai Desert Classic a fortnight ago, Willett added a 69 to his opening 65 in Kuala Lumpur to finish eight under par alongside Miguel Tabuena, Soomin Lee and Jorge Campillo.
But the world number 13 revealed he was not feeling 100 per cent after a round containing four birdies and two bogeys on the composite course at Royal Selangor Golf Club.
"I'm struggling a bit with my body," Willett said. "My energy levels collapsed on the back nine and I started making a few silly mistakes. I'm going to see the physio then catch up on some rest, because I'm feeling very tired.
"But the flags were also quite tricky today and the wind's picking up a bit, so I can't see the scoring being too ridiculous. And I would've taken eight under after two rounds.
"I probably hit four or five different tee shots to what I did yesterday, mainly due to the wind direction and also the pin positions. It's a brilliant golf course in that respect, because you don't have to move the tees around too much to change the hole, if you change the flags it can still affect what you do from the tee.
"I love the design. You can still be aggressive and take the hole on if you want, but if you hit it in the rough you lose all control for your second shot. So it really makes you think out there."
Despite the tougher conditions, overnight leader Nathan Holman was quickly among the birdies to extend his advantage, the 24-year-old picking up shots on the third, fourth and sixth to enjoy a two-shot lead on 10 under.
Holman, who won his maiden European Tour title in the Australian PGA Championship in December, had yet to drop a shot this week and holed from seven feet for birdie on the par-five 13th to extend his lead to three.
England's Richard Bland was four off the pace after picking up two shots in the first seven holes of his round, with Rafael Cabrera-Bello and KT Kim on six under with six and five holes remaining respectively.
Former world number one Martin Kaymer was level par with six to play and a shot outside the current projected halfway cut.