Kiradech Aphibarnrat was in the clubhouse with a 1-stroke lead on Thursday when the first round of the Maybank Malaysian Open was suspended due to thunderstorms.
Aphibarnrat, an Asian Tour regular, fired a 7-under 65 at Kuala Lumpur Golf & Country Club before rain and lightning halted play for the day.
Scott Jamieson is currently the biggest threat to overtake the leader at 6- under through 10 holes, while Edoardo Molinari, Anders Hansen and Gregory Bourdy are in the clubhouse at minus-6.
"It's too hot to get frustrated so you just have to stick in there. It's extreme and very difficult for everyone," said Hansen, a three-time European Tour victor who is seeking his first win on the circuit in four years.
Victor Dubuisson and S. Murthy both shot 67s, while Charl Schwartzel made up a large group knotted at 4-under. The former Master champion has a pair of birdies and an eagle through 11 holes.
Three-time major winner Padraig Harrington shares 15th place after an opening- round 69, but world No. 3 Luke Donald, coming off a tie for fourth at the PGA Tour's Tampa Bay Championship, is towards the bottom of the leaderboard after carding a 74.
Matteo Manassero, the 2011 champion at this event, is 1-under through 10 holes.
Thailand's Aphibarnrat, who placed fourth last week in India, began his day on the 10th tee and had four birdies against a single bogey during his outward nine. The 23-year-old then picked up a hatrick of birdies starting at the third and closed with another birdie on his last to secure the clubhouse lead.
Bourdy, who last won on the European Tour four years ago, got off to a blistering start with five birdies in his first seven holes, but the 30-year- old managed just two gains during his inward nine and dropped a shot on the par-4 14th.
"It's great to start the tournament like this" said Bourdy. "Six-under is a good score on this course."
Hansen was just 1-under through nine, but he holed his iron approach for eagle on the par-4 second and closed with a hatrick of birdies to grab a share of second place.
"It's always nice to finish with three birdies," he said. "I plodded along all day and all of a sudden the putts started dropping at the end."
NOTES: Play will resume at 7:45 am (local time) ... Bourdy is a three-time European Tour winner ... Donald is playing in this event for the first time ... Schwartzel won the Alfred Dunhill Championship earlier this season and has four top-10 finishes in six events worldwide this year ... The Asian Tour and the European Tour co-sanction this event ... Last year, Louis Oosthuizen posted rounds of 66-68-69-68 to cruise to victory just one week after his playoff loss to Bubba Watson at the Masters. Oosthuizen is not on hand to defend his title.