Golf: Ireland's Padraig Harrington warmed to the defence of his Iskandar Johor Open title with a seven-under par 64 on Thursday to sit just one shot off the lead after a rain-hit opening round at the €1.48 million event.

Harrington chipped-in for eagle at his fourth hole and offset a single bogey with six birdies to equal his best round of the season and sit in a tie for second place behind in-form Dutchman Joost Luiten.

Frenchman Gregory Bourdy and Australia's Marcus Fraser are the two players alongside the three-times major winner in the clubhouse at the Horizon Hills course.

Luiten shot an eight-under par 63 prior to a late afternoon thunderstorm and after a one-hour wait for the weather to clear, officials suspended play for the day with 78 players yet to complete the first round, which will conclude early on Friday.

The 40-year-old Harrington was delighted as he seeks to successfully defend his title and also end a spell of more than three years without a European Tour win at an event that was sanctioned solely by the Asian Tour until this year.

"It's always nice to put in a good showing when you come back to defend particularly with the way I started so it suggests I might put in a good performance this week," Harrington said.

"It's just nice to be up there near the top of the leaderboard and nice to be playing well."

Luiten's score will not count as a new course record nor will it be noted as the Dutchman's lowest-ever round in his two years full-time on the European Tour due to a "preferred lie" rule in effect following recent heavy rain in the area.

Despite missing out on putting his name in the record books, the 25-year-old Bleiswijk-born Luiten was delighted with his round just four days after he shared fifth place at the Singapore Open.

"On this course you can really attack the pins, especially as you have a lot of wedges in your hands," Luiten told reporters.

"I found most of the fairways off the tee and that put me in a great position to make some birdies. I played well in Singapore, which gave me a lot of confidence to carry into this week."

The ambitious former amateur star has not only set himself a target of a first European Tour victory but also to finish the season high enough on the money list to secure a place at next year's British Open.

"I'm lying 33rd on the money list so it's already been a great season, and I'm looking forward to playing the Dubai World Championship," he said.

"But if I can finish top-30 and gain exemption into The Open next year, that would round off a great season for me."

Earlier, former world number four Henrik Stenson of Sweden completed a four-under 67 to sit in a tie for 10th place before announcing he would undergo knee surgery next month after struggling through a disappointing season.

"It hasn't bothered me that much in swinging the club or hitting shots but it's not great when I am walking hilly courses and also there are a lot of noises coming from my knee, particularly when I squat down to read putts," the 35-year-old said.

"This is the first real injury I've had in my career and touch wood, I won't have any more."

Stenson's 2009 Players Championship win ensures he is exempt for events on the U.S. PGA Tour for 2012 but is having to rely on invitations in Europe next year for the first time in his 13-year professional career.

"It hasn't been a great year but I've managed to play a bit better the last couple of months and hopefully I can have a really good this week before going into hospital," the world 181 added.