ARDMORE, Pa. — Phil Mickelson made his first birdie on his last putt. Billy Horschel never missed a green. It was all they could do to barely break par against Merion, which is turning out to be the real star of this U.S. Open.
Nearly half the field did not finish the second round when it was suspended because of darkness Friday. Moments after the horn sounded to stop play, Mickelson opted to finish his round and drilled a 20-foot birdie putt for 2-over 72. That gave him a share of the clubhouse lead with Horschel, a former Gator who made it as easy as possible by hitting every green in regulation for 67.
They were at 1-under 139.
The 68 players who failed to complete the round were scheduled to resume beginning at 7:15 this morning.
Even with the round not finished, it was becoming clear this Open might be up for grabs until the very end.
Tiger Woods, who grimaced with every shot out of the rough because of pain in his left elbow, was at 3-over 143 and still very much in the game. So was Rory McIlroy with the same score.
"I don't know how anyone is going to separate too far from the field," Mickelson said. "There might be a hot round (today), and they might get a hot round on Sunday, but unlikely to be the same player."
No one was hotter than Horschel, 26 and playing in his first Open since he was a 19-year-old in college at Florida.
Horschel hit all 18 greens in regulation, a stellar achievement at a regular tour event, let alone the U.S. Open. It sent U.S. Golf Association officials searching for hours to find the last time anyone failed to miss a green in the toughest test in golf.
Records of that detail go back only to 1989. The last documentation of someone doing that was Johnny Miller when he closed with 63 at Oakmont to win in 1973.
"I didn't know I hit every green until I walked off 18," said Horschel, who won his first tour event in April at the Zurich Classic. "It's a cool thing. But … it's not the first time I've hit all 18 greens. I've done it plenty of times in my career. Obviously, it's at a U.S. Open, but I think the softness of the greens helped that."
The long day, brought on by storm delays Thursday, began with cool conditions and patches of light rain that eventually gave way to sunshine. That led players to wonder how much tougher Merion will be once it starts to dry out.
Luke Donald (72), Justin Rose (69) and Steve Stricker (69) finished their rounds and were at par 140.
One of the day's surprises was amateur Cheng-Tsung Pan of Taiwan. Pan played nine holes at 2 under and was at par, along with Ian Poulter, 1 under for his round through 14 holes.
Pan, 21, is a junior at the University of Washington. He missed the cut in his other Open appearance, in 2011, saying he was too excited and had too many distractions. This time, he said, he embraced the pressure.
"I feel I belong to that kind of place," he said. "I'm not saying I'm good enough, but I love this kind of feeling, and the competition is great."