But the 40-year-old Swede showed no signs of rust as he raced to the top of the leaderboard with a flawless 64 in Abu Dhabi, the only venue on the European Tour's 'Desert Swing' where he has yet to record a victory.

Best of the Irish Paul Dunne is four shots off the lead on four under after a 68 on day one, while Darren Clarke ended three over.

The Wicklow man was one under after the front nine but then clocked up four birdies in a row on the 10th, 11th, 12th and 13th before a bogey at the second-last.

"It must be that lack of practice that does it," Stenson said after starting on the 10th and racing to the turn in 30, before picking up further shots on the seventh and ninth.

"Lack of sleep, lack of practice, but I'm obviously delighted with that score. I think I scored a bit better than I played but I kept it under control somewhat, hit a couple of close iron shots and made the putts.

"Wasn't too much stress out there after all."

Asked how much practice he had done in the off-season, the world number four told Sky Sports: "I was working on my putting, some short game, hit a couple of buckets last week and then flew to Sweden (on Monday).

"I was there for the sports awards, came down here on Tuesday morning, so very limited preparations. That might be the way forward."

At eight under par, Stenson held a two-shot lead over three-time winner and Ryder Cup team-mate Martin Kaymer, whose 66 was matched by England's Oliver Fisher and Thailand's Kiradech Aphibarnrat.

England's Tyrrell Hatton was a shot further back, with Ryder Cup captain Thomas Bjorn on four under after six birdies and two bogeys in a 68.

Defending champion Rickie Fowler and fellow American Dustin Johnson had to settle for opening rounds of 72, while Masters champion Danny Willett struggled to a 74 which included a triple-bogey seven on the 14th.

Scotland's Marc Warren made it a four-way tie for second after carding eight birdies and two bogeys in his 66, the 35-year-old looking to improve on a best finish of 26th in 11 appearances in the event.

"I felt as though I finished the season last year pretty strongly and got off to a good start again today," Warren said. "It just proves that what I've been doing the last couple weeks, what I've been working on, is hopefully going to take me in the right direction.

"I started on 10 and made birdie there and birdied 11 as well. I was three under after four, so it was the perfect start after seven or eight weeks off."

The best golf of the afternoon starters was coming from Spain's Rafa Cabrera Bello, the Ryder Cup star covering his first 11 holes in five under par.