Sepp Straka, the 161st ranked player in the world, tied an Olympic record with an 8-under-par 63 and was sitting with a one-shot lead at the end of the first round of the Tokyo Games men's golf tournament on Thursday.
Representing Austria, Straka played bogey-free golf and hit 16 of 18 greens to leap to the top of the leaderboard, which featured 40 competitors under par at the end of the day at Kasumigaseki Country Club.
Due to dangerous weather conditions, play was halted for approximately two hours from 1:55 p.m.
Belgium's Thomas Pieters, Mexico's Carlos Ortiz and Thai Jazz Janewattananond were tied for second behind Straka when play was paused. The Belgian and Mexican had played 18 holes and the Thai had three remaining.
Upon resumption of play, Jazz birdied 18 and moved into sole second place at 7-under.
For host Japan, Masters champion Hideki Matsuyama shot a 2-under 69, and Rikuya Hoshino got off to an even-par start.
"If I can't control my shots I won't be able to improve my score, like you saw on the back nine," Matsuyama said.
"I hope to move up the leaderboard tomorrow so I'll have a chance at contention. I hope to play great at both the long and short game," he said.
Straka carded eight birdies as one of the three-player leading group that teed off at 7:30 a.m. The 28-year-old is the son of an Austrian father and American mother, and has his twin brother as his caddy for the Olympics.
"It was just a steady round. I really hit the ball well and I didn't put myself into trouble. I took advantage with the putter," said Straka, adding the key to the course is consistently finding the fairways.
"I got hot with my irons, especially my short irons, my wedges. I was really knocking down the flagstick and really tried to stay aggressive," he said.
In his first appearance back since testing positive for COVID-19 earlier this month, Matsuyama had four birdies and two bogeys in an up-and-down round in which he was battling a wayward driver.
He sank a 2.5-meter putt for his first birdie on the third hole, then found the bunker off the tee at the par-5 fifth, but played a superb recovery and got his second birdie. He made back-to-back birdies on seven and eight, but struggled with his swing after the turn.
The 60-man field does not include Jon Rahm of Spain or Bryson DeChambeau of the United States, the No. 1 and No. 6 male golfers in the world, respectively, as they were diagnosed with coronavirus during testing before they were set to depart for Tokyo.
The Olympics set a single-day record for coronavirus cases, with organizers confirming 24 new positives on Thursday, which included three athletes.
Men's golf will see a new Olympic champion in the absence of 2016 Rio gold medalist Justin Rose of Great Britain, who failed to qualify for the Tokyo Games. The sport returned to the Olympics in Rio de Janeiro for the first time in 112 years.
Unlike regular pro tournaments, there will be no cut, so all 60 players will play the full four rounds.