Holmes leads crowded leaderboard by 1 at The Open

J.B. Holmes fired a 5-under 66 in Round 1 of the Open Championship to lead by one shot at Royal Portrush and kick off the season's final major.

The 37-year-old - who won the Genesis Open earlier this year - dropped a shot on his first hole Thursday before playing the remaining round bogey-free.

Ireland's Shane Lowry sits alone in second place after holding the clubhouse lead for most of the day at 4-under par.

Brooks Koepka, Jon Rahm, and Sergio Garcia are among a group of 13 players who all share the third spot. Koepka is in prime position to become the first player since 1934 to finish first or second in all four majors in the same calendar year.

Here's how the top of the leaderboard stands after Round 1:

While plenty of players managed to figure out Royal Portrush, two of the game's biggest names didn't. Tiger Woods and Rory McIlroy are at 7-over and 8-over, respectfully, in what were forgettable days for both.

Hometown favorite McIlroy was out early Thursday and stumbled out of the gate. He made a quadruple-bogey 8 on No. 1 after going out of bounds with his first tee shot. Later, the Northern Irishmen missed a tap-in for bogey and finished his day with a triple-bogey.

Woods replicated McIlroy's lack of success. He only made a single birdie on the day for his worst opening round in 21 trips to the Open Championship.

Phil Mickelson also struggled to a 5-over 76 to hold a share for 129th.

Round 2 gets underway Friday at 1:35 a.m. ET.