Perfect teamwork helped China claim three gold medals in shooting and diving on Tuesday at the Tokyo Olympics, as triathlete Flora Duffy made history by winning Bermuda its first ever Olympic gold medal.

At the end of Day 4 action, host Japan remains on top of the medal standings with 10 gold, 3 silver and 5 bronze medals, followed by the United States (9-8-8) and China (9-5-7).

Chinese shooters flexed their muscle at the Asaka Shooting Range again by sweeping both titles in air pistol and air rifle mixed team events on Tuesday, adding to their earlier haul of six medals at Tokyo 2020.

Pang Wei, a four-time Olympian and 2008 Olympics gold medalist, and Jiang Ranxin shot to gold in the 10m air pistol mixed team, the first mixed team event in the history of the Olympic Games. Pang and Jiang fired shots of 10.1 and 10.7 points respectively in the deciding round, outclassing the ROC pair of Vitalina Batsarashkina and Artem Chernousov with a 16 to 14 score.

In the 10m air rifle mixed team event, the first gold medallist of Tokyo 2020, Yang Qian, and the men's 10m air rifle men bronze medallist Yang Haoran beat Americans Mary Carolynn Tucker and Lucas Kozeniesky in a tight and often tied match.

"This Olympics are special and important for us, because China in the last Olympics didn't do so well. So here we are transforming that and getting medals everywhere," Yang Haoran said of China's medal spree in shooting, which reached eight medals after the fourth day of competition.

China's gold streak continued in the women's synchronised 10m platform, where Chen Yuxi and Zhang Jiaqi stormed to a resounding victory and extended China's perfect record in the event since the 2000 Olympics.

The Chinese teenage duo topped the rankings with 363.78 points, well ahead of Jessica Parratto and Delaney Schnell from the United States in 310.80 points.

Chen and Zhang's triumph means that Chinese divers have won the event at every edition since it was included in the Olympic program at Sydney 2000.

After a weather-induced 15-minute delay due to the threat of a typhoon, the triathlon competition kicked off before witnessing Duffy finish the race in 1 hour, 55 minutes and 36 seconds, one minute 14 seconds over silver medalist Georgia Taylor-Brown from Britain.

"I'm so grateful that I could achieve a personal dream here of winning an Olympic medal," said Duffy. "But this is bigger than me, this is going to inspire the youth of Bermuda and everyone back home that competing on the world stage from a small island is really possible."

Kuo Hsing-Chun won Chinese Taipei's first gold at these Games when she set three Olympic records en route to victory in the women's weightlifting 59kg category.

A breakthrough was made by silver medalist Polina Guryeva of Turkmenistan, who also gave her country its first ever Olympic medal.

Some upsets were staged on Tuesday, as home favorite tennis player Naomi Osaka crashed out of the women's singles third round at the hand of the 42nd-ranked Czech Marketa Vondrousova 6-1, 6-4.

"I definitely feel like there was a lot of pressure for this," admitted Osaka about playing on home court.

Another setback for the Olympic hosts came in table tennis, where 18-year-old medal hopeful Tomokazu Harimoto was defeated by Darko Jorgic from Slovenia in full sets in the men's singles round of 16.

In volleyball, defending champions Chinese women's team lost their second straight match at Tokyo 2020, going down 27-29, 22-25, 21-25 to world No. 1 side the United States in Pool B preliminaries.

U.S. spiker Jordan Thompson scored a game-high 34 points, while China captain Zhu Ting, who is still suffering from a wrist injury, had a team-high 18 points.

In football, China's women's team were crushed by the Netherlands 8-2, failing to progress through the group stage after recording one draw and two defeats.

As many as 23 gold medals are on offer on Wednesday in rowing, swimming, road cycling, diving, equestrian, rugby, gymnastics, fencing, judo, weightlifting and 3x3 basketball.