Peter Hanson, Louis Oosthuizen and Phil Mickelson burst into a share of the lead on a dramatic day at The Masters Tournament.
American Mickelson birdied the tenth and 12th and then holed a curling 25 foot eagle putt at the next to join fellow American Matt Kuchar, Swede Peter Hanson and South Africa's 2010 Open Champion Louis Oosthuizen on six under par.
Lee Westwood had been one of the seven players to have at least a share of top spot in the third round - that was when he birdied the long second - but in his 56th attempt to win a Major he failed to get up and down from sand on the seventh and then missed a par putt of little more than a foot at the ninth. He had putted for birdie from only ten feet moments before.
That gave Westwood a front-nine 37 and at joint ninth on three under he was still very much part of the title race, as was Padraig Harrington, who birdied five of the last six holes for a joint best-of-the-day 68 for four under.
Scot Paul Lawrie was three under with seven holes remaining, but 52 year old Fred Couples, joint halfway leader with Jason Dufner, managed only 39 for the outward half to stand two under.
Hanson turned in 34 and birdied the 12th and 14th, while Kuchar sank a bunker shot at the fourth and also birdied the seventh and ninth for an outward 33.
Oosthuizen was playing with Westwood, the man he pushed into second spot at St Andrews two years ago, and after bogeying the fourth he birdied the sixth, seventh and eighth.
Justin Rose climbed into a share of third by covering the first 14 holes in three under, but he rolled back into the lake on the 15th, took six there and four-putted the short next for a double bogey. In the end he handed in a third successive 72.
It was an ever-changing position at the top. Hanson reached seven under with a 15 footer on the 15th, Oosthuizen joined him by hitting his tee shot to within three feet at the 12th and then Mickelson played a wondrous flop shot to six feet on the 15th and birdied as well.
Kuchar, though, three-putted the 13th for bogey to leave it as a three-way tie between the other three, while Lawrie birdied the 13th to be in the group on four under.
Westwood birdied the 11th, but had two in sand on the next and with a bogey was back down to 12th and four back.
Hanson was simply inspired. He had the first birdie of the day on the 17th from 25 feet and at the last hit his approach to two feet.
In went the putt for his seventh birdie of a flawless 65 - and on nine under the 34 year old Ryder Cupper led by two in only his second Masters Tournament.
Hanson had heard the roars for Mickelson throughout the back nine - and another was to come.
The left-hander birdied the 18th for the third day in a row and so with a 66 was only one behind in his quest for a fourth Green Jacket.
Hanson still was not sure to lead on his own heading into the final round as Oosthuizen also birdied the 17th to join Mickelson on eight under.