Updated

As only he can, Phil Mickelson produced a wild finish Sunday at the Scottish Open, eventually defeating Branden Grace with a birdie on the first playoff hole.

Mickelson could have locked up the victory in regulation, but he missed a 5- foot par putt at the last and dropped into a tie with Grace at 17-under-par 271.

Back at the scene of that potentially costly bogey, Mickelson dropped his third shot from the sand within inches of the cup and tapped in for a birdie 4.

When Grace missed his 25-foot downhill birdie attempt, Mickelson had his first official European Tour victory at this final tuneup before the British Open in dramatic and opportune fashion.

"This is really cool," he said. "I have been coming here for some time and had some opportunities and I almost let it slip away today. To come out on top was terrific."

Mickelson and Grace carded matching 3-under 69s at Castle Stuart Golf Links to overcome a 2-stroke overnight deficit. The left-hander grabbed sole possession of the lead for the first time with a birdie at the 14th and he maintained that advantage until the last, which Grace parred a group ahead.

Mickelson was on the fringe at the par-5 18th in three, but his unlikely 3- putt kept hope alive for the South African, who recorded four victories on the European Tour a season ago.

"I was so mad at myself for mentally losing my focus that I came out on that 18th pretty focused to make a four," continued Mickelson.

Overnight leader Henrik Stenson remained in contention for much of the day before stumbling to bogeys on three of his final six holes. The 37-year-old Swede carded a 1-over 73 and ended in a tie for third with JB Hansen (71) at 15-under.

Martin Laird (68), John Parry (72) and Gareth Maybin (71) tied for fifth at 14-under, while Nicolas Colsaerts (69) and Raphael Jacquelin (72) shared eighth at minus-13.

Mickelson was a runner-up here in 2007 and it appeared he was headed for another finish outside the winner's circle after a double bogey at the first and another bogey at the third after a gain at the second.

The slow start had Mickelson four off Stenson's pace, as the two-time European Ryder Cup performer opened with a pair of pars around a birdie at the second.

Mickelson righted himself with three straight birdies from the fourth, and Grace remained in the mix with eight straight pars to start, but it was the 22-year-old Hansen who charged to the top spot near the midway point.

A quadruple-bogey 9 at the second appeared to dash Hansen's hopes of a maiden European Tour title, but the young Dane bounced back with five straight birdies and added another gain at the ninth for an outward 34.

Around the turn, Hansen grabbed the outright lead with his fourth birdie in four rounds at the par-4 10th.

Stenson briefly moved back on top with consecutive birdies from the 10th, but his bogey at the 13th allowed Hansen to reclaim the lead with a birdie at the 14th.

Both Hansen and Stenson faded down the stretch, as the former bogeyed three of his last four holes and the latter dropped consecutive shots from the 16th.

Their slide opened the door for Mickelson, who birdied Nos. 11 and 12 to pull even, then grabbed the outright lead, his first of the tournament, with a birdie at the 14th.

He kept that 1-stroke advantage with three straight pars before delaying his eventual victory with his short par miss at the 72nd hole.

"It's important to me, and it's probably the biggest challenge of my career hitting the shots that are required here. And so to win here and to play well here, finally win on a links golf course, it really means a lot to me, and it also builds my confidence heading into future Scottish and British Opens," he said.

NOTES: Mickelson was making his 11th Scottish Open appearance. He lost in a playoff to Gregory Havret at this tournament in 2007 ... Mickelson became the first American to win the Scottish Open since Tom Lehman in 1997 ... This was Mickelson's 48th professional victory worldwide ... The last Scotsman to win this tournament was Colin Montgomerie in 1999.