PHIL Mickelson coolly sank an 18-foot birdie putt at the last to regain a one-shot lead.

It came after a low-scoring third round at the Colonial Invitational on Saturday.

A stroke in front overnight, former champion Mickelson overcame a shaky start with a brilliant display of shot-making on his way to a five-under-par 65.

Seeking his 34th PGA Tour title, the American ended a sweltering day at Colonial Country Club by posting a 12-under total of 198.

His birdie on the 18th green edged him ahead of Australian Rod Pampling (63) and Canada's Stephen Ames (64), both in the outright lead during the third round.

'It was a nice way to finish,' Mickelson said. 'I was trying to get one more birdie on those last two and I was able to get it on 18.

'There might be an advantage to not being in the last group because as I was watching guys making birdies in front of me today, it was a lot more difficult to stay patient.

'I think there's an advantage to going out early and making a run, and that's how I was able to win here in 2000.'

Recent history appears to favour Mickelson. The last six winners at Colonial have held at least a share of the 54-hole lead while Mickelson has triumphed 19 times out of 26 on the PGA Tour when leading going into the final round.

Pampling, three behind overnight, reeled off eight birdies in the first 14 holes to go two ahead but stumbled with bogeys on 16 and 17 before a birdie at the last put him level with Ames at 11 under.

Ames piled up six birdies in a blemish-free display and narrowly missed a 12-footer at the last to join Mickelson at 12 under.

IN CONTROL

Pampling covered the front nine in a sizzling five-under 30 and picked up further shots at the 11th and 12th to stretch two ahead.

He also birdied the 14th before surrendering the outright lead to Ames with bogeys on 16 and 17.

Ames briefly edged ahead by sinking a 24-footer to birdie the 16th before being caught by Pampling's birdie at the last.

Mickelson then regained a share of the lead with a moment of magic at the 15th. After driving into the left rough, he struck an aggressive approach that landed five feet from the flag to set up his sixth birdie.

Although he narrowly missed a birdie attempt at the par-four 17th, Mickelson broke clear of the pack with his 18-footer at the last.

Reuters