Mickelson remains on top at Merion

Phil Mickelson remained atop the leaderboard after a crazy ending to Saturday's third round at the U.S. Open Championship.

Mickelson birdied the long par-3 17th, but gave that shot back at the last as his par putt stopped a roll or two short of the hole. He carded an even-par 70 in round three on the East Course at Merion Golf Club to finish 54 holes of the year's second major at 1-under-par 209.

"I love being in the thick of it. I've had opportunities in years past, and it has been so fun, even though it's been heartbreaking to come so close a number of times and let it slide," said Mickelson, who is a five-time U.S. Open runner-up. "But I feel better equipped than I have ever felt heading into the final round of a U.S. Open. My ball striking is better than it has ever been. My putting is better than it has been in years, and I feel very comfortable on this golf course. I love it."

The left-hander had fallen out of the lead, but his even-par closing was enough to keep him atop the leaderboard.

Hunter Mahan and 2011 Masters champion Charl Schwartzel both bogeyed the final two holes. They both shot 1-under 69 to end alongside Steve Stricker (70) in second place at even-par 210.

Luke Donald coughed up three shots in the final two holes en route to a 71. He ended 54 holes at 1-over 211, and he was joined there by Justin Rose (71) and second-round co-leader Billy Horschel (72).

Three-time champion and world No. 1 Tiger Woods struggled to a 6-over 76 and tumbled into a share of 31st at 9-over 219.

Woods birdied the first to move to plus-2, but that was it. He faltered to three bogeys in a 4-hole span from the third to dip to 5-over. Woods bogeyed 10, 12, 16 and 18 to drop 10 strokes behind Mickelson.

"The first two days, I had like three 3-putts and I was four shots off the lead, and I missed a boatload of putts within 10 feet. So I really wasn't that far off," Woods explained. "If I clean up the round and don't 3-putt, I'm one shot back starting out today. So basically, I just didn't have the speed right this week and it certainly showed."

World No. 2 Rory McIlroy, who played with Woods each of the first three rounds, was just one stroke better as he posted a 75 to end three rounds at plus-8.

McIlroy didn't fare much better than Woods. He birdied the first and seventh, but had four bogeys in between. The reigning PGA Champion dropped shots at the ninth and 11th before making his final bogey at 15.

"If you're not on your game 100 percent, you get on the wrong side of the greens and it's just frightening because I didn't feel like I played too badly," said McIlroy. "I missed a few shots here and there, and I was trying on every shot out there and I was trying to get myself back into it, but it's tough. If you're just not 100 percent on top of your game, it's going to expose some of your flaws or weaknesses."

While the top two players in the world failed to get anything going, those battling for the lead were playing well, until the final two holes.

Schwartzel was tied for the lead at minus-2 and was in the midst of six pars in a row from the 11th. He stumbled to bogeys on the final two holes to dip to even-par.

Mahan poured in three birdies in a 4-hole span from the 10th to get within one shot of the lead. He join the leaders at minus-2 with a birdie at 16. But like his playing partner, Schwartzel, Mahan bogeyed the final two holes to fall back to even-par after three rounds.

As tough as their endings were, the third player in the group, Nicolas Colsaerts, dropped one more stroke than they did. Colsaerts' drive on 18 ended under a tree and that led to a triple bogey.

Rose, who was one off the lead after a birdie at 13, also bogeyed the final two holes to end two back at plus-1.

The steadiest player down the stretch was Stricker. He started with eight pars in a row before stumbling to a double bogey at No. 9. He bounced back with birdies at 10 and 12 to move to even-par. He closed with six pars in a row.

That left it to the last group, which included Donald and Mickelson. Donald's tee shot at the 17th came up short, right in a bunker. He couldn't get up and down for par from there.

At the last, Donald's approach came up well short in the thick, right rough. He hacked his third across the green, then got up and down for bogey to drop one back.

"It might be a little bit of fatigue, but it was both yardages I had to get a little extra out of the 2-iron. And my poor swings is when I attack too hard from the top and I get out of sync and they go right," said Donald, who had three birdies and a bogey through 16 holes. "And unfortunately those holes are playing tough. I should have done better. It was disappointing. But I'll take the positives out of today, a really solid 16 holes of golf that I played and I'm only two back."

Mickelson's tee shot at the long par-3 17th rolled within 10 feet of the hole and he poured that birdie putt in. That 2-shot swing with Donald was key to giving Mickelson the lead.

Mickelson, who turns 43 on Sunday, knocked his second shot over the green at the last, from 274 yards out. He chipped to about seven feet, then saw his par putt stop inches short. He would have been two clear if that putt dropped.

"I'm really looking forward to it. I'm looking forward to facing the challenge of Merion again. It's a wonderful test," Mickelson stated. "I think that there are holes that are obviously very difficult pars, some of the hardest par holes that we have ever played. But we have also have a number of birdie opportunities, much more so than in years past. So there's a great mixture of holes and it's been fun to test ourselves."

NOTES: Mickelson has won 29 of the 42 times he was the 54-hole leader in PGA Tour events, but he has won three of the four times he was the 54-hole leader in a major ... Stricker has three top-10 finishes in his previous 17 U.S. Open starts ... Defending champion Webb Simpson posted his second straight 75 to end three rounds at 11-over 221, which was good for a share of 44th.