Austrian Sepp Straka has set a cracking pace as Australia's medal hopefuls struggled to keep up during the first round of the Olympic men's golf championship.
Straka fired an Olympic record-equalling eight-under-par 63 to claim a one-stroke lead over Thailand's Jazz Janewattananond at the Kasumigaseki Country Club on Thursday.
Out in the first group of the day, Straka was safely in the clubhouse when thunderstorms in Tokyo forced a two-hour suspension of play.
The 28-year-old - who'd missed the cut in six of his previous seven US PGA Tour starts - was bogey-free during his blistering round.
With his putter running hot, Straka rattled in birdies on the third, fifth, sixth and eighth holes to reach the turn at four under.
No let up on the back nine, he collected another four more birdies in five holes coming home to leave the 60-man field playing catch up early in the 72-hole, no-cut event.
Janewattananond was six under through 15 holes when the horn blew signalling the weather warning, but the lengthy stoppage didn't slow his momentum as he picked up one more shot upon the resumption to finish the day outright second.
Belgian Thomas Pieters and Mexican Carlos Ortiz both carded 65s to be equal third at six-under, with Dane Joachim B Hansen and Venezeulan Jhonattan Vegas sharing sixth a further shot back on a cosmopolitan leaderboard.
Players from 13 different nations occupied the top 13 spots after round one.
But the USA's top three seeds, Irish superstar Rory McIlroy and Australian pair Marc Leishman and Cameron Smith battled to stay in touch.
Xander Schauffele and Patrick Reed, a late call-up to replace the COVID-positive Bryson DeChambeau, were the best of the American big guns with three-under 68s, one better than newly-crowned British Open champion Collin Morikawa and McIlroy.
World No.4 Justin Thomas had to settle for 18 straight pars to be level the card along with Smith, who let slip a promising start with two bogeys on the back nine, including a sloppy six on the par-5 14th.
Leishman also endured a frustrating Games debut, mixing three consecutive birdies from the 13th with two bogeys in a one-under 70.
"The conditions were fairly easy," Leishman said.
"I fought back well there on the back nine. Three birdies in a row.
"It's really important tournament to get off to a good start because I feel like if you don't finish in the top three, it doesn't really matter.
"So I've still got that chance; three good rounds and you can try and
Australian Associated Press