PEBBLE BEACH, Calif. - Despite two dozen victories on the PGA Tour and one memorable major, Phil Mickelson wound up in new territory through two rounds at the Pebble Beach National Pro-Am.

This is the first time Lefty has had at least a share of the 36-hole lead two consecutive weeks.

And he has never led by this much.

"It's different. But I enjoy it," Mickelson said Friday afternoon after a 5-under 67 at Poppy Hills, which gave him another tournament record and, more importantly, a four-shot lead over Mike Weir.

After a course-record 62 in the opening round at Spyglass Hill, Mickelson threatened to turn the AT&T Pebble Beach National Pro-Am into a runaway with five birdies on his first nine holes to build a six-shot lead.

He was even par the rest of the way in light rain that fell over the Monterey Peninsula, but that was still good enough to finish at 15-under 129 and break by two shots the 36-hole tournament record.

Now he heads to Pebble Beach, which has played the easiest of the three courses this week without any wind. But the goal remains the same - making as many birdies as possible, building on the lead, hopeful of turning the final round Sunday into a walk along the beach.

Weir birdied the last three holes for a 67 at Pebble Beach, leaving him at 11-under 133.

Andrew Magee had a 68 at Spyglass, while Kevin Sutherland (70) and Paul Goydos (68) were at Pebble Beach and wound up at 9-under 135.

All of them are chasing Mickelson, which appears to be a tough task.

"He's a world-class player," said Darren Clarke, who had a 66 at Pebble Beach and was seven shots behind. "He is up and down a little bit, but whenever he is on, he shoots fantastic scores and he is obviously playing well this week."

Mickelson has a tendency to go low, so it was surprising that a four-shot lead going into the weekend was the largest of his 13-year career as a pro.

"Given my propensity to throw up high numbers, I'm not surprised," Mickelson said with a laugh.

That hasn't been the case lately.

Mickelson shot 60 in the second round last week in Phoenix, then closed with rounds of 66-68 for a five-shot victory, the largest margin of his career. In his last 11 rounds dating to the Bob Hope Classic, he is 53 under par.

As usual, it was entertaining.

Mickelson pulled his opening tee shot on No. 10 so badly that he had to take an unplayable lie, then pitch out sideways. That left him a 6-iron into the green, and he holed a 30-footer for par.

He hooked another tee shot on the par-5 12th, but it caromed off a tree and left him an opening for a 7-iron to the green and a simple two-putt for birdie.

Then came an 8-iron that he had to carve out of the woods for another unlikely birdie.

"I just cut it around the tree," Mickelson said. "It was not that big of a deal."

By the time he made the turn, he was 5 under for his round and had a six-shot lead. But he played the front nine at Poppy in even par with hardly any fireworks on a cool, damp afternoon that made scoring on all three courses a little tougher.

Weir, who has finished in the top four here the last two years, made an early charge to get to 10 under for the tournament, dropped two straight shots along the cliffs, then finished with three birdies putts from about 10 feet.

"I like the position I'm in," Weir said. "Spyglass is a tough test, and hopefully I can have a good round there and give myself a shot Sunday."

Defending champion Vijay Singh has some work to do - not to become the sixth repeat champion at Pebble, but simply to get a tee time Sunday. Singh had a 40 on his second nine at Poppy Hills - traditionally the easiest course in the rotation - and had a second straight 73.

He was 17 shots out of the lead, and likely needed a 68 at Pebble Beach to make the cut.

Clarke is among the most well-known Europeans, in part because of his stylish clothes and big cigars, and because his two victories in the United States were World Golf Championships.

He returned to golf after a difficult offseason, learning that his wife was diagnosed for the second time with breast cancer. Doctors have been encouraged by her progress, and Clarke played in South Africa three weeks ago.

"She wanted me to get back and start playing again, just get back and try to get a little bit more normality than we have been," Clarke said.

Lee Westwood, his friend on the European tour, is traveling with him and shot 69 at Pebble Beach to finish his two rounds at 7-under 137, along with Davis Love III (72).

Charles Howell III had a 71 at Spyglass Hill and was among those at 8-under 136.