It was the big-hitter’s lowest score on the European Tour and he needed it too, given the pressure exerted by American world number 11 Chris DiMarco and Miguel Angel Jimenez, of Spain.

Stenson revealed he has been fighting a bug and has also been troubled by a niggle in his back, hindering his preparations.

“Maybe I should keep this bug,” he smiled. “It’s been a bit of a funny week. I pulled my back on Sunday practising in Dubai, so I’ve been having treatment for a couple of days.

“And then for the last couple of days I had a bit of a stomach complaint so I wasn’t feeling at all well and it was a struggle on Friday.

“I was tired coming up the last couple of holes on Friday but I managed to finish birdie, birdie. And then I shoot this score today!”

After his eagle at the 10th, Stenson could not replicate his front-nine form coming back and it looked as if he would have to settle for a share of the lead until he pulled the second eagle of the bag, putting from just four feet at the par-five 18th.

He would have shared it with DiMarco, who parred the last to bring to a close a round of 63 that began with a double bogey but quickly developed into a birdie-sinking display.

Nine were recorded, as well as an eagle at the 10th, and the 37-year-old saluted the work of his stand-in caddie, wife Amy.

“When I made the double on the first hole, she said, ‘okay it’s over, let’s just go from there,”’ the world number 11 noted.

“I feel like I slow down a lot more with her, which is great, because my biggest problem is that I get too fast.

“I went out and continued hitting great shots and I’m very excited with what I shot.

“It’s been good for her to be there for every shot, to see everything and see how my thinking is out there. I think she understands it a little bit more now.”

Jimenez ended the day a shot further back at 14 under and despite putting eight birdies, and registering no bogeys, he was unhappy that he failed to take more of his opportunities.

He said: “I missed two chances for birdies on the last two holes which if I had holed them I would have been right up there with the leader.

“I put a few shots close to the hole but didn’t make them at all, which was a little frustrating. But it was still a good round.

“Overall, I am very happy at the way I am hitting the ball and this is pretty good having been away from golf for about five or six weeks.”

Of the other big guns, who had got lost in the pack when the wind blew in the first two rounds, Colin Montgomerie exceeded his expectations by a shot in shooting a 65.

It was the same score carded by Sergio Garcia, who, at 12 under, is a shot clear of the Scot and within touching distance of the leaders.

Like Jimenez, he bemoaned his short game. “I played very, very well today and I hit so many good iron shots, and it’s a shame because I was going nicely and it could have been an unbelievable round. Unfortunately, some putts didn’t drop.”

Poor putting also accounted for Vijay Singh’s 69, his five birdies were offset by two bogeys, and he is seven adrift of Stenson.

Friday’s overnight leader, Charl Schwartzel, of South Africa, is still firmly in the hunt at 13 under, alongside Argentine Ricardo Gonzalez.