PGA Tour rookie Cameron Young shot a bogey-free, 8-under-par 64 to establish the first-round lead at The Open Championship as Tiger Woods struggled.
Close behind, Rory McIlroy of Northern Ireland polished off a 6-under 66 for sole possession of second.
Australia's Cameron Smith was three strokes back at 5-under 67, and Englishman Robert Dinwiddie birdied the 18th hole after 10 p.m. local time to tie Smith for third.
Eight players were tied at 4-under 68: world No. 1 Scottie Scheffler, Dustin Johnson, Talor Gooch, England's Lee Westwood, Norway's Viktor Hovland, Australia's Brad Kennedy, Kurt Kitayama and English amateur Barclay Brown.
New Zealand's Ryan Fox is tied for 35th on 1-under.
Seven of Young's eight birdies came over the first 12 holes. One of the longest drivers on the PGA Tour, Young drove over the green at the short par-4 ninth, 12th and 18th holes, getting up and down for birdie each time.
In Young's debut at The Open, he came up one shot shy of tying the lowest first-round score in championship history. The 25-year-old has yet to win as a professional, but he has five top-three finishes on the season, including a tie for third at the PGA Championship in May.
"I think we picked tee shots that were smart, and that kind of kept a lot of the bunkers out of play," Young said on the television broadcast. "And then made a few putts early, which kind of set the tone for the day. All those things just added up to not feeling too hard out there, even though I know it could be impossible for me tomorrow."
McIlroy, the four-time major winner and No. 2 player in the world, made three straight birdies at the fifth through seventh holes. He rebounded from his lone bogey at No. 13 with a birdie at the par-5 14th. At the 18th, he left an 84-foot eagle putt inches to the right of the cup for his final birdie.
After top-10 finishes at each of the first three majors this year, McIlroy once again is in good position to end a major drought that dates to 2014.
"I just have to go out and play the same golf that I've played today, the same golf that I've played over the last few weeks," McIlroy said. "I've been playing well. I've been swinging the club well. And I think it's better if I don't think about it that much and I just go out and play golf and try to shoot some good scores on one of my favorite golf courses in the world."
Smith, winner of The Players Championship in March, drained a right-to-left, 55-foot birdie putt at the par-4 second to jump-start his round. He finished with six birdies and one bogey.
"It was probably some of the best lag putting I think I've ever done," Smith said. "My putt on the second managed to go in from a fair distance. That was pretty decent. But had so many -- seemed like I had so many 80-, 90-, 100-footers out there today and did a good job of getting them down in two."
Dinwiddie, 39, is making his first major start in five years and entered the week ranked No. 1,779 in the world. He played bogey-free golf until a stumble at the 16th, but he got that stroke back at No. 18 when he chipped onto the green to set up a 5-foot birdie putt.
Tiger Woods started his week with a 6-over 78. Woods, who won The Open at St. Andrews in 2000 and 2005, was back competing in a major after skipping last month's U.S. Open to rest his surgically repaired leg.
The 15-time major champ's opening drive came to rest in a divot in the fairway. His second shot bounced into a creek in front of the green, leading to a double bogey. Woods plummeted to 6 over through seven holes, partly due to another double bogey. He rebounded a bit with consecutive birdies at the ninth and 10th holes, but never truly found his short game.
Two-time Open champions Padraig Harrington of Ireland and Ernie Els of South Africa carded rounds that defied Father Time. Harrington, 50, is tied for 13th at 3-under 69 with the likes of Xander Schauffele, Bryson DeChambeau and Chile's Joaquin Niemann.
Els, 52, used four birdies between the eighth and 12th holes to get to 5 under early on. But after bogeying No. 16, his drive at No. 17, the Road Hole, found the Old Course Hotel out of bounds. Els made double bogey and wrapped up a 2-under 70.
Defending champion Collin Morikawa opened with an even-par 72, tied with a group that also included Phil Mickelson (three birdies, three bogeys).
-Reuters