TOKYO - U.S. gymnast Simone Biles dropped out of the women's team event after one vault at the Olympic Games in Tokyo on Tuesday and tennis player Naomi Osaka exited the Games days after lighting the Olympic flame.

After a disappointing attempt in the first rotation of the women's team event, Biles was signified by an 'R' on the competitor list before the bars began, indicating she would not continue in the competition.

The International Gymnastics Federation confirmed she would play no further part in the team event, but said she would still receive a medal if the heavily favoured U.S. ended up on the podium.

Osaka, who lit the Olympic cauldron on Friday to open the Games after a one-year postponement, looked out of sorts and never settled into a rhythm as she lost 6-1 6-4 in the third round to Czech Marketa Vondrousova.

"I think it's maybe because I haven't played in an Olympics before and for the first one to be here was a bit much," she said.

It was her first tournament since she pulled out of the French Open in May. The women's tennis tournament has now lost both of its top draw cards after Australia's world number one Ash Barty was beaten in the first round.

Osaka's departure left Japan without its best known global sporting figure in the Olympics, one whose multi-ethnic background contrasts with the image of an insular and male-dominated country that emerged in the run-up to the event.

The Games are taking place under a state of emergency and without spectators, an unprecedented event in the history of the modern Olympics.

(Reporting by William Mallard, Rozanna Latiff, Ju-min Park, Farah Master, Philip O'Connor, Sam Nussey, Linda Sieg and Antoni Slodkowski; Writing by Mari Saito and David Dolan Editing by Stephen Coates/Michael Perry/Ed Osmond/Ken Ferris) ((william.mallard@thomsonreuters.com; +81 3 4563 2749;))