Hideki Matsuyama survived a rollercoaster round to leave himself four shots off the clubhouse lead at 1-under 69 after the first round of the World Golf Championships-Bridgestone Invitational on Thursday.
Matsuyama's inconsistent game at the Firestone Country Club included seven birdies and six bogeys, the 25-year-old getting off to a birdie start on No. 10 and reeling off four birdies in a row from the 13th to make the turn at 3-under par, only to endure a meltdown on the back nine with four bogeys.
Thomas Pieters of Belgium topped the leaderboard after shooting a near-flawless 65, rolling in a 30-foot birdie putt on his final hole for a one-shot lead over Scotland's Russell Knox and two strokes ahead of six other players tied for third.
"It was an awkward round. I thought I would do a little better but it's hard to play well on tournament day," said Matsuyama.
"My short game was not so good on the back nine. I kept missing the fairways too. You don't play too many rounds that feature seven birdies and six bogeys. It's a reflection of my current condition," he said.
Elsewhere for Japan, Satoshi Kodaira is 53rd after a round of 73 and Hideto Tanihara shot a 74 to sit at 62nd. Seventy-six players are competing in the 72-hole, no-cut event with a total purse of $9.75 million.