A weekend showdown of golf's top stars was set Friday at the US Open as two-time major winner Collin Morikawa seized a share of the lead while Jon Rahm and Rory McIlroy were one stroke adrift.
Seventh-ranked Morikawa fired a four-under par 66 and American Joel Dahmen, who shot 68, joined him on five-under 135 after 36 holes at The Country Club.
Second-ranked defending champion Rahm, third-ranked McIlroy and Americans Hayden Buckley, Aaron Wise and Beau Hossler shared third on 136.
"No one has taken it deep so far and run away," Morikawa said. "But you know what, right now my game feels really good.
"The last few days is a huge confidence booster for me heading into this weekend, and hopefully we can make some separation somehow."
Morikawa won last year's British Open and the 2020 PGA Championship and the 25-year-old American could find himself 75% of the way to a career Grand Slam by Sunday night.
"I can't really talk about what it would be like to win this one. I've got to focus on tomorrow," Morikawa said. "I've got to make sure I don't run out of steam... I've just got to figure out a way to focus a little bit deeper and really get dialed in for the next 36."
Starting on the 10th tee, Morikawa made birdie putts of 10 feet at the 12th hole, 13 feet at the par-5 14th, 14 feet at the 17th and 33 feet at the first.
After his lone bogey at the fourth, Morikawa dropped his second shot at the par-4 eighth four feet from the cup but missed his eagle putt and settled for birdie.
"I knew the tempo was a little off," Morikawa said. "It just happened to be a bad stroke. So I'm not too worried about it really."
McIlroy, who endured a double-bogey disaster at the third hole, sank a 15-foot birdie putt at the 12th, drove the green in two to set up a tap-in birdie at the par-5 14th and sank a 12-foot birdie putt at 17.
"I'm in a good place," McIlroy said. "I'm really happy with where my game is at and I think that's the most important thing."
McIlroy, chasing his first major title since 2014, comes off a victory in last week's PGA Canadian Open. Not since 1934 has a player won the week before and then captured the US Open.
"I have to go out with the mindset this week that I'm going to try to win my first again," McIlroy said. "I'm playing as good a golf as I've played in a long time."
Top-ranked Masters champion Scottie Scheffler, with an eagle and two birdies in the last six holes, was on 137.
"I just stayed real patient," said Scheffler. "If a few putts had gone in instead of around, it could have been a really special day."
Rahm, a back-nine starter, holed a 12-foot eagle putt at the par-5 14th, drove the green to set up a birdie at the par-4 fifth and chipped from the rough ahead of a tap-in birdie at eight.
"It's great for the game of golf that the highest-ranked players and the best players are up there," Rahm said. "It's fun for all of us because we all want to compete against the best and beat the best."
Dahmen, 34, won his only PGA title last year in the Dominican Republic. He missed a 10-foot birdie putt at 18 that would have given him the lead alone.
"It's all kind of a blur, which is probably a good thing," Dahmen said. "Handled nerves pretty well out there. It's going to be quite a weekend."
- Mickelson misses cut -
Six-time major winner Phil Mickelson missed the cut on 11-over 151. The 52-year-old US lefthander was among 15 rebels from the Saudi-backed LIV Golf Series facing US PGA Tour stars.
US major champions Dustin Johnson and Patrick Reed were the best of the LIV players in the field on 141, with Bryson DeChambeau and Richard Bland also making the cut on 142. But LIV players were a combined 53-over on Thursday and 36-over on Friday.
With the richest purses in golf history, LIV Golf has lured talent from the PGA Tour, which banned 17 current and former members last week after they played LIV's debut event in England.