Kuala Lumpur - Sweden's Rikard Karlberg sunk seven birdies for a seven-under-par 65 to take a two-stroke lead in the first-round of the CIMB Classic in Malaysia, while Spanish star Sergio Garcia lurked four shots back.
American defending champion Ryan Moore turned in six birdies of his own to lead a pack of golfers just three strokes off Karlberg's pace on 68.
The Swede, who has struggled this year to overcome a stubborn viral infection and said he "almost stopped enjoying the game", credited his strong start to a decision to just shake off the negative feelings and relax.
"I just went out there and tried to be as relaxed as possible and just have fun," he said.
Karlberg had five birdies on the front nine at Kuala Lumpur Golf and Country Club and cemented his lead with two more on the final two holes.
World number four Sergio Garcia, the highest-ranked golfer in the field, was in striking distance after entering the clubhouse with a three-under 69.
Garcia, 34, started brightly, notching four birdies over his opening nine, but could manage no more the rest of the way and suffered a bogey down the homestretch.
But the Spaniard, who has seen a revival in his play this year including a January Qatar Masters win and runner-up showing to world number one Rory McIlroy in the Open Championship, was pleased.
"I felt like I played quite well. Obviously I didn't hole a lot of putts. I hit some really good putts that I had quite a lot of lip-outs, but other than that, it felt good," he said.
Patrick Reed, a bright spot for the USA in its latest recent Ryder Cup loss to Europe, was among several entrants who finished the day at two-under after shooting a 70.
England's Lee Westwood, who won on the same course in the Malaysian Open in April, had an up-and-down day to finish at even par, tied with a group of golfers including this past season's FedExCup champion Billy Horschel.
Westwood, a former world number one, turned in a card featuring two birdies and an eagle three on the par-five fifth, but also two bogeys, and a double bogey on the par-four 16th.
"I struggled with the speed of the greens more than anything, but made a nice eagle at five, which got me back to level par. So not too much damage done," he said.
Co-sanctioned by the PGA Tour and Asian Tour, the CIMB Classic offers the winner $1.26 million and 500 FedExCup points.
Last year's winner, Ryan Moore of the United States, is back to defend, as compatriot Jason Dufner continues his comeback.
Jason Dufner, the American 2013 PGA Champion, who returned to competitive play last week in Australia after nearly three months off due to a neck injury, could muster only a two-over 74.
Leading first-round scores Thursday in the $7 million CIMB Classic at the par-72 Kuala Lumpur Golf and Country Club:
65 - Rikard Karlberg (SWE)
67 - Billy Hurley III (USA), Brian Stuard (USA), Angelo Que (PHI)
- Tim Wilkinson (NZL), Ryan Moore (USA), Kevin Streelman (USA), Davis
Love III (USA), Noh Seung-yul (KOR), Jeff Overton (USA), Prom Meesawat
(THA), David Lingmerth (SWE)
69 - Ryo Ishikawa (JPN), Scott
Stallings (USA), Sergio Garcia (ESP), Kevin NA (USA), Jonas Blixt (SWE),
Danny Lee (NZL), Matt Every (USA), Will Mackenzie (USA), Kevin Chappell
(USA), Nicholas Thompson (USA)
70 - Patrick Reed (USA), Hideki Matsuyama (JPN)
72 - Lee Westwood (ENG), Billy Horschel (USA)
74 - Jason Dufner (USA)