Phil Mickelson (67) clubhouse leader

ARDMORE, Pa. -- A cross-country flight, little sleep and more weather woes didn't stop Phil Mickelson from a memorable day at the U.S. Open at Merion Golf Club.

The five-time U.S. Open runner-up, who returned to California earlier in the week for his daughter's eighth-grade graduation and didn't get back to suburban Philadelphia until the wee hours Thursday morning, shot a 3-under 67 to take the clubhouse lead.

First-round play Thursday, interrupted by two separate rain delays, was suspended due to darkness, with Luke Donald leading at 4 under through 13 holes.

"Yeah, it might be abnormal, but it actually worked out really well," said Mickelson, who had four birdies and a bogey on the water-logged, par-70 course, which played 6,966 yards. "I got all my work done at Merion when I was here a week and a half ago. I knew exactly how I wanted to play the golf course, given the conditions, given different wind conditions, clubs I was going to be hitting, where I was going to be and the shots I was going to have.

"So I didn't feel I needed more time at Merion. What I needed was to get my game sharp, to get my touch sharp. And having a nice practice facility and nice weather for the last couple of days allowed me to do that. So it worked out great on both ends."

It was Mickelson's best score in relation to par in the first round of a U.S. Open since 1999 at Pinehurst -- the year he was faced with the possibility of leaving early due to the impending birth of his daughter, Amanda, who will turn 14 on June 21. That ended up being one of his five runner-up finishes at the U.S. Open.

Mickelson's best opening score at a U.S. Open was 4 under in 1992 at Pebble Beach, his first professional tournament, although he missed the cut.

Mickelson, who will turn 43 on Sunday, left Merion on Monday night to return to San Diego, figuring he could practice better at home. He had planned all along to attend Amanda's eighth-grade graduation Wednesday, which was at 9 p.m. ET. Mickelson, who has his own plane, said he boarded at 11 p.m. ET, slept some on the flight, landed in Philadelphia at 3:30 a.m. ET, got another hour of sleep, then arrived at Merion in time to warm up for his 7:11 a.m. ET tee time.

He three-putted the first hole for bogey but remarked to his longtime caddie, Jim Mackay, that many of his best rounds have come after starting that way. Sure enough, Mickelson did not have a bogey the rest of the way. But it was still a long day, as the round was interrupted by lightning and then substantial rain that delayed play for approximately 3½ hours. Mickelson played just five holes before the stoppage, then returned to finish the remaining holes on the back nine (rounds are starting at Nos. 1 and 11) before making birdies at the first, seventh and ninth holes. He concluded with a par at the 10th.

Of those who finished, Mickelson was leading by two strokes, with Belgium's Nicolas Colsaerts shooting 69 to sit alone in the clubhouse in second place. Several players, including 2011 Masters champion Charl Schwartzel, Rickie Fowler and Jason Day, shot 70.

The first round was to resume at 7:15 a.m. ET Friday, and the forecast called for drier weather for the rest of the week.

Donald, in search of his first major championship, birdied Nos. 11-13 to surge past Mickelson and into the lead.

Tiger Woods appeared to hurt his left hand after trying to gouge out of the deep rough on the opening hole. He grimaced and shook his left wrist again after hitting a 5-wood out of the rough on the fifth hole. He already had three bogeys though five holes before starting to make up ground with a 50-foot birdie putt on the par-4 sixth hole.

Woods, however, failed to take advantage on the short stretch of holes in the middle of the round, and was shaking his hand again after shots out of the rough on the 10th and twice on the 11th. He was 2 over for his round and had a 4-foot par putt on the 11th when play was stopped for the day.

"I've got a lot of holes to play tomorrow," Woods said. "And, hopefully, I can play a little better than I did today."

Masters champion Adam Scott, playing with Woods and Rory McIlroy, was 3 under through 11 holes, while defending U.S. Open champion Webb Simpson was 2 under through eight holes. McIlroy was 1 under.

Lee Westwood got the full Merion experience. He was 3 under when his approach on the 12th hit the wicker basket -- the signature at Merion, replacing traditional flags -- and bounced off the green, leading to a double-bogey.

Merion, which hasn't hosted the U.S. Open since 1981, was expected to be vulnerable, given all the rain the past week. The course has been softened considerably, which often leads to good scoring. But only Mickelson and Colsaerts were under par among the first 78 players who finished.

"This was as easy as this golf course is going to play," Mickelson said. "We had very little wind. We had soft fairways, soft greens and we had no mud balls. So we had the best opportunity to score low. And we are all struggling because it's such a penalizing golf course. It's penalizing if you miss the fairways, very difficult if you miss the greens, and it's not a given to two-putt on these greens. They're some of the most pitched greens we have ever seen, and they're very quick.

"It's a course that's withstood the test of time, and it's challenging the best players in the world this week. As the week wears on and the conditions get a little bit drier, a little bit firmer, I think the course is going to get even more difficult and the scores are going to hover very close to par."

Mickelson, who has won 41 times on the PGA Tour, including four major championships, has had nothing but disappointment at the U.S. Open. He was second in 1995, '99, 2002, '06 and '09. The second-place finish to Geoff Ogilvy in 2006 was particularly tough, as Mickelson held the lead on the 72nd tee, only to make a double-bogey.

"He's had a crazy last 24 hours," said Keegan Bradley, who played with Mickelson on Thursday. "Sometimes that helps, not thinking about it. He's going to get rest and he'll be in great shape.

"He played very well. He missed the fairway and laid up. Is putting awesome, made a couple of ridiculous up-and-downs, is playing well."

Information from The Associated Press was used in this report.