For the second straight day at Merion Golf Club, play was suspended due to darkness setting in. Billy Horschel took a one-under lead into the clubhouse and will share it with Phil Mickelson when play opens up on Saturday.
Behind the co-leaders, Justin Rose and a slew of Europeans headline those tied for third at even par. Tiger Woods and Rory McIlroy, pair mates for the first two days, both finished three-over after two rounds with identical scores of 70 on Friday.
2013 Masters winner Adam Scott shot a 75, narrowly avoiding the cut at seven-over.
2013 U.S. Open Leaderboard
*For a complete look at the 2013 US Open leaderboard, click here (via PGATour.com).
Golfers will have to hit the course early again to finish the second round if they had not already done so when the whistled sounded, and by the time the second round is officially over early Saturday morning, the cut will have siphoned off a large chunk of golfers that showed up on Thursday.
But Horschel was the story of the day at Merion, blazing through the course with four birdies to just one bogey en route to a three-under 67. He also hit all of his greens in regulation on Friday, the first time anyone has done that at a major in 20 years.
ESPN's Trey Wingo had the tweet to showcase Horschel's consistent brilliance on Friday:
Billy Horschel hit all 18 greens in regulation in today's 67...first time at an open in 20 years...
Mickelson is the biggest name among the co-leaders, though, and he followed up a strong round on Thursday with another one on Friday. He entered the 18th and final hole of the day one stroke back, but in typical Mickelson fashion, birdied it to wind up with a 72 for the round and one-under overall.
Eileen Blass-USA TODAY
The unpredictability of majors has been on full display this week at Merion, and Friday was no different. If you look at the leaderboard, two amateurs are currently in the top 10, headlined by one who is trying to become the first amateur since 1933 to win the event (via PGA Tour Media):
Cheng-Tsung Pan has 2 birdies in 1st 5 holes, moves to even. 5 amateurs have won 8 @usopengolf titles, most recently John Goodman (1933).
Since Day 2 action is technically not over, there's a chance that some of the golfers near the top of the leaderboard could move this number up to five- or six-over with a solid round of golf.
However, with what we've seen so far, combined with an extremely early round for those who haven't yet finished their second round at Merion, there's a good chance the Horschel-Mickelson one-under will hold up and keep things around seven- or eight-over.
Either way, we know that the field is going to be condensed big-time after the opening few holes of the second-round holdovers are completed on Saturday morning. Assuming things go as planned, a long list of golfers will be watching from the gallery on Sunday, including a few notable names that you'll see below.
Notable Projected Cuts
Martin Kaymer (+8, F)
Dustin Johnson (+8, F)
Brandt Snedeker (+8, F)
Tim Clark (+8 through 17)
Keegan Bradley (+12, F)
Marc Leishman (+13, F)
Angel Cabrera (+15, F)
Jim Furyk (+16, F)
Ryan Nelson is sitting at five-over through roughly three quarters of two rounds (through nine when play was stopped on Friday), but this birdie putt was a thing of beauty on No. 13—his only birdie in the second round.
Jason Day was one of the standout finishers at the Masters this year, and he's in a nice position to at least stay within striking distance at the U.S. Open at three-over with 14 holes completed in his second round.
This shot on No. 12 was one of the best of the day:
Rickie Fowler also finished five-over, but he has a tendency to wind up in the notable-shots section in almost every tournament he enters. This shot on No. 10 did the trick on Friday:
And to close things out, here's Mickelson's birdie on No. 18, which gave him a share of the lead and a chance to continue his push to avenge his five runner-up finishes in previous U.S. Opens:
*All GIFs via Bleacher Report's U.S. Open Day 2 Stream.
Follow Bleacher Report FC Ethan Grant (@DowntownEG) on Twitter.