US Open Golf 2018: How to View Saturday's Live Leaderboard Scores, Updates

The 2018 U.S. Open has proved to be a tough test for the world's best golfers. Jordan Spieth, Jon Rahm, Rory McIlroy and Jason Day—who rank fourth, fifth, sixth and eighth in the Official World Golf Ranking, respectively—are all headed home after they missed the cut at Shinnecock Hills in Southampton, New York.

However, world No. 1 Dustin Johnson seems to be immune to the course's obstacles, as he carded a four-under 136 and took a four-shot lead on the field heading into the weekend. DJ earned a three-under 67 on Friday, which included a 45-foot birdie putt to extend his lead.

Johnson wasn't the only notable Friday performance, though, and two more from a couple of golfers are discussed below.

You can follow all three (and the rest of the field) via the tournament's official website on desktops and through the U.S. Open app on mobile devices. Live leaderboard scores and updates are available via both means.

Tyler Duncan

Only 14 players shot under par on Friday, and just four of them carded a four-under 66 or three-under 67 to lead the way. Three of those players are in the top 12 of the Official World Golf Ranking (Tommy Fleetwood, Brooks Koepka and Dustin Johnson).

The last one is ranked 402nd, and that's Tyler Duncan, a solid 28-year-old ball striker who played collegiately at Purdue.

The 2018 calendar year got off to a rough start for Duncan, as he missed nine of his first 10 cuts. However, he's been in a groove of late, making the weekend at six straight tournament events dating back to the Zurich Classic of New Orleans in late April.

Duncan is 49th on the PGA Tour in strokes gained off the tee and 57th in strokes gained around the green. Those ball-striking skills helped him on Friday, as he finished first in greens in regulation. The issue for Duncan this year has been the short game, most notably a 195th-place ranking in strokes gained putting.

That wasn't as much of an issue Friday, however, as Duncan finished near the middle of the pack in putts per round.

The former Boilermaker's performance vaulted him into a tie for 14th place after he was sitting two shots behind the cut line on Thursday. A run to the top of the leaderboard is a tall ask, but it will be interesting to see if Duncan can follow up on his excellent Friday performance. He tees off with Jason Dufner at 1:31 p.m. ET on Saturday.

Brooks Koepka

The 2017 U.S. Open champion's tournament did not start well. After shooting a five-over 75 on Thursday, his second round began on shaky ground, as he bogeyed two of the first four holes to drop himself to seven-over. That mark placed him in cut-line territory.

However, Koepka bounced back with a brilliant 11-hole stretch thanks to six birdies that catapulted him into a fourth-place tie at one-over. As expected, his ability to boom drives down the fairway was a big help, as he finished fourth on Friday in driving distance (326.60 yards).

But Koepka was able to also keep the ball in the fairway, which helped set up shorter approach shots. That, in turn, created makable birdie putts down the stretch (all of his birdies were off putts within 14 feet). For the day, he finished tied for fifth in greens in regulation.

Although Johnson is the clear favorite at this point, Koepka could certainly give the world No. 1 player a run, especially if he catches fire again as he did Friday.

He's proved that he can win (and dominate) on the major stage thanks to his 16-under performance at the U.S. Open last year, but Koepka simply fares well any time there's a major. Dating back to 2013, he has made his last 15 major cuts, and he hasn't finished worse than 21st since the 2015 Masters.

Unless Johnson runs away with the tournament on Sunday and takes an insurmountable lead, expect Koepka to hang around the top of the leaderboard deep into the weekend. He'll tee off with Ian Poulter at 2:37 p.m. ET.