Zheng Qinwen on Wednesday became only the second Chinese tennis player to reach the singles semi-finals at an Olympics, beating German veteran Angelique Kerber 6-7(4) 6-4 7-6(6) in the quarter-finals in a three-set thriller.

After two tough sets, Kerber, who won a silver medal at Rio 2016, took the lead in the third to 4-1 and received a standing ovation from an enthusiastic French crowd after saving a huge break point.

Having run out of steam on a hot and humid Philippe Chatrier court and lost 10 points in a row, she bounced back to 4-4. But Zheng's powerful shots allowed her to win the tiebreak.

Reaching the quarter-finals, at a tournament the 36-year-old had said would be her last, was the former world number one's best performance this year after returning from maternity leave in January.

The German had lost in the first round of this year's three Grand Slams so far, the Australian and French Open followed by Wimbledon.

Zheng reached a career-high ranking of No. 7 after her runner-up finish at the Australian Open.

On the men's side, Novak Djokovic and Carlos Alcaraz shrugged off crushing humidityto stay on course for an Olympic gold medal showdown.

Djokovic, seeking a first Olympic title at Roland Garros to add to his record-breaking collection, defeated German left-hander Dominik Koepfer 7-5, 6-3, becoming the first man to reach four singles quarter-finals at the Games.

Alcaraz brushed aside Roman Safiullin, the Russian playing in Paris as a neutral, 6-4, 6-2. (Reuters/AFP)