Swedish golfer Madelene Sagstrom has set the early pace as Australians Minjee Lee and Hannah Green endured rollercoaster first rounds to stay in medal contention at the women's Olympic individual stroke play in Tokyo.
Sagstrom defied sweltering heat to fire a blemish-free five-under-par 66 to claim a one-stroke lead over American world No.1 Nelly Korda and India's Aditi Ashok on Wednesday.
Korea's defending Olympic champion Ingbee Park and New Zealand's resurgent former world No.1 Lydia Ko also stalked the leaders in oppressive conditions, making hydration stations, ice packs and wet towels the order of the day.
But it was Sagstrom who stayed the coolest, five birdies in her first 10 holes doing the trick as the world No.75 kept Korda and company at bay at the Kasumigaseki Country Club.
Korda rattled in six birdies and could have carded any old number had her uncooperative putter been able to cash in on more of the 23-year-old's laser-like approaches.
Park is in a tie for seventh after a two-under 69 marred by a bogey at the last, with Ko a further shot behind Sagstrom in a tie for 15th despite a double-bogey six mid-round.
Lee and Green both returned even-par 71s to be five shots off the pace in a share of 23rd position.
Playing her first round since winning her maiden major championship in France last month, Lee reeled off six birdies but she never managed to get lower than two under after also racking up six bogeys.
"If I can get rid of the bogeys, then I would have posted a good score. So that's golf," she said.
"The bogeys I made, all of them were really soft. So maybe tomorrow just try and eliminate them make as many birdies as I did today.
"I'm just going to take it day by day because it's so hot. Yeah, hopefully take the positives into tomorrow."
After a nasty double-bogey on the second hole, Green scrambled well to battle back to also finish level with the card.
"I mean, I felt like I played a lot worse than the score. So to have even par pretty happy with," Green said.
"It's only round one."
Australian Associated Press
