Shane Lowry was two off the first-round lead at the Memorial Tournament after a fine opening 69 in Dublin, Ohio, where half a dozen players top the leaderboard.
The Offaly man was one over at the turn but hit four birdies on the back nine, including on 18, to finish three under and in a share of 11th.
Rory McIlroy was one shot further back after making five birdies but also dropping three shots.
Seamus Power was level-par 72, having posted three birdies and a double bogey from 14 to 17.
World number three Cameron Smith split seven birdies with two bogeys en route to a score of five-under 67 among a six-way tie for the lead alongside Canada's Mackenzie Hughes, South Korea's KH Lee and the American trio of Cameron Young, Luke List and Davis Riley.
The opening round at Muirfield Village Golf Club was a fruitful one for the players, with just two strokes separating the top 20 players.
Earlier, Japan's 2021 Masters winner Hideki Matsuyama was disqualified from the tournament for the use of a non-conforming club.
Matsuyama, who earned the first of his eight PGA Tour wins at the 2014 Memorial Tournament, was disqualified from the Jack Nicklaus-hosted event after painted lines were discovered on the face of his three wood.
If marked the first time the former Masters champion has been disqualified from a PGA Tour event.
PGA Tour senior tournament director Steve Rintoul said images of the club were posted online and his team only learned of them after Matsuyama had used it on the first tee. Had he not used the club, he could have kept playing.
Rintoul said his team approached Matsuyama on the second hole to ask if he had used the club and the former Masters champion was forthright about it.
"The material was applied to the face for alignment for Hideki to set the ball inside the circle of the lines. That's actually the center of the face," Rintoul told reporters.
"And applying a small, discrete dot with a Sharpie (marker) to help you with alignment is fine. We have players who do it all the time. But the amount of substance that was up on the face of the club, when we sent it to the USGA, their equipment standards guys, it was just excessive.
"And that's what could affect - could affect - the performance of the ball."
Matsuyama, playing in a group alongside Rory McIlroy and Patrick Reed, was three-over-par 39 when he reached the turn at Muirfield Village after a double-bogey at the second hole and bogey at the sixth.
