Olympics: Everything you need to know right now

World champion pole vaulter Sam Kendricks' pursuit for Tokyo glory came to an abrupt end on Thursday when he and an Argentinian rival tested positive for Covid-19. 

Here's what you need to know about the Tokyo Games:

CORONAVIRUS CHILLS

US Olympic and athletics officials said that Kendricks had tested positive and, in line with local rules, was transferred to a hotel for isolation. German Chiaraviglio of Argentina confirmed he was out of the Games as well and was isolated in a hotel.

"We are all pretty spooked out right now," said Swedish world record holder Armand Duplantis, whose bar battle with the American was expected to be one of the highlights of track and field. 

Duplantis said he had plans to meet up with Kendricks on Wednesday but was lucky to have missed them.

JAPAN CHEERS

Barred from attending events, Japanese residents are celebrating their athletes' success by queuing up for photos around an Olympic monument near the city's National Stadium.

Host nation Japan is enjoying a stellar Games, tied with China for 14 gold medals atop the table. The United States was in third with 13 golds and 37 medals at about 6:45 p.m. Tokyo time.

Banner headlines in the Japanese press and bursts of confetti on the internet hailed the ascent of 19-year-old gymnast Daiki Hashimoto, who became the youngest-ever Olympic champion in the men's individual all-around event.

Some residents, such as Ryoko Yoshioka, believe Japan may have tasted bigger success if there wasn't a ban on spectators.

"There are many Japanese supporters out there, and it surely brings power to our athletes," said Yoshioka.

A RELAY FOR THE HISTORY BOOKS

China's 4x200 freestyle relay team thought beating Canada to win bronze was a realistic target ahead of the women's final. Winning gold in a world record time was beyond their wildest expectations.

"We didn't expect to win the race because the Americans and Australians are so strong," said Zhang Yufei, who only found out she had to swim in the relay after her Olympic record gold in the 200m butterfly an hour earlier.

With an early lead, final swimmer Li Bingjie fought off a surging Katie Ledecky to keep ahead of the United States and clock a winning time of 7:40.33, with hot favourites Australia third.

All three teams finished under the previous world mark of 7:41.50 set by the Australians in 2019.

Australia's swimming coaches came out swinging in defence of their selection decisions after former Olympic gold medallists Ian Thorpe and Giaan Rooney, along with the Australian media, criticized the decision to choose a different team for the heats and the final, leaving out in-form teenager Mollie O'Callaghan.

WHAT WE'RE WATCHING FOR

The women's all-around gymnastics final was set to begin at about 8 p.m. local time with the US expected to offer a steely defence of the crown even without Simone Biles.

Can Kei Nishikori get a hometown boost and upset world no. 1 Novak Djokovic's quest for the golden slam? The tennis battle started on Thursday evening in Tokyo on centre court, after officials pushed back matches in response to player complaints about the sweltering heat. Djokovic took the first set 6-2 and was 3-0 up in the second set.

Japan's Aaron Wolf powered through to the judo final on Thursday as the host nation looks to add to its tally of golds after Hamada Shori's victory earlier in the evening.

France will vie with the Russian Olympic Committee (ROC) for the title in the women's foil team event after trouncing Italy in the semi-finals at the Tokyo Games. The U.S. will vie with Italy for the bronze.

China was set to add to its gold medal haul in table tennis when compatriots Chen Mung and Sun Yingsha face off in the women's singles.