Alexander Noren shot an 8-under 64 to take a two-stroke lead in the weather-shortened first day of the Malaysian Open on Thursday.
Masters champion Charl Schwartzel (73) struggled after only arriving in the country only a day earlier, while Rory McIlroy (69) was five shots behind Noren in a tie for ninth.
Most competitors finished the first round, but some will have to wait until Friday morning because inclement weather forced play to be stopped.
Schwartzel carded a 39 on the front nine at Kuala Lumpur Golf and Country Club.
"I didn't sleep very well," Schwartzel said. "I'm struggling to focus. The golf swing is tight ... I was swinging so good last week and the weeks before that. The body isn't responding right now, but it will come."
Noren started on the back nine and birdied the 10th, 11th and 12th holes before a bogey on No. 14. The Swede got back on track with two more birdies on the 16th and 17th.
The 2009 European Masters champion started his second nine with more birdies at the first, third and fifth holes and closed out his round with a birdie on No. 9.
"I had two weeks off and I worked a lot harder on my game," Noren said. "I felt lucky at times when they kept rolling in, but you have to have that sometimes."
Italian teenager Matteo Manassero, who finished his round with four straight birides, was two behind at 66. Manassero turns 18 next week and said it would be a "nice way to celebrate" by winning in Malaysia.
"It will be good to get to a major age," said Manassero, who became the European Tour's youngest winner when he captured the Castello Masters Costa Azahar last year. "I played well and holed a few nice 20-footers. I like the grainy greens. I feel like I can hit every putt solid and it gives me confidence putting."
Jeev Milkha Singh of India and Darren Beck of Australia were a further stroke behind at 67 in a tie for third, while British Open champion Louis Oosthuizen (69), top-ranked Martin Kaymer (70) and defending champion Noh Seung-yul (73) trailed.
(This version CORRECTS Corrects McIlroy to five shots behind in 2nd paragraph.)