FINAL ROUND LEADERBOARD US unless stated -28 P Mickelson -15 JM Olazabal (Spa), Z Johnson -14 JJ Henry, R Goosen (SA) -12 J Byrd Selected others: -10 L Donald (Eng) -6 D Howell (Eng) -4 I Poulter (Eng) -3 P Harrington (Ire)

The left-handed American led from start to finish to leave the field trailing in his wake on 28 under.

Mickelson, 35, carded a closing 65 with Spain's Jose Maria Olazabal and American Zach Johnson in second.

England's Luke Donald shot 66 for 10 under, while David Howell was six under, Ian Poulter was four under and Padraig Harrington three under.

Mickelson equalled the course record at the TPC Sugarloaf in Georgia with an opening 63 to lead by one before stretching his advantage to six shots with a second-round 65.

He narrowly missed becoming only the second player in over 50 years - after Tiger Woods at the 2000 US Open - to hold a 10-stroke advantage going into the final day of a tournament.

He sank his chances by sending two balls into the lake short of the 18th green to finish with a 67 and an eight-shot lead on Saturday.

But he continued his dominance on Sunday with an eagle and two birdies on his first five holes of the back nine, when play was halted due to the threat of lightning.

Although he bogeyed the 15th, the American was too far ahead of his rivals and finished on a high with another eagle at the par-five 18th.

The scores will not be anywhere as low at Augusta Phil Mickelson

"It was certainly a fun week. I was very pleased with the way I played obviously and I felt like I was playing well," said Mickelson.

"I had some good practice days but it really means a lot to actually have the scores reflect the way I felt I was playing. In fact, maybe even a little bit lower. So that was nice.

"I feel as though I'm starting to get really sharp as far as distance control and some of the areas I've been working on.

"I think those areas are going to be critical next week for a good performance at Augusta, especially given the changes and how difficult it's playing. But I can promise you, the scores will not be anywhere near."

Donald, whose challenge was derailed with a quadruple bogey nine on the 18th in this third round, said: "Obviously Phil's playing great, but I might have got close to second but for that nine yesterday.

"I'm pretty pleased with how I played today - it could have been even lower - and it's good for my confidence going into next week."

Ireland's Harrington signed off with a 75 and said: "I lost all confidence on reading the greens.

"I'll focus mainly on that when I get to Augusta, but I think the putter is fine because I've been putting well on the practice green."