Jackson's announcement does come in the wake of her pulling up with an apparent injury late in a race in Hungary three weeks ago.

The Serbian top seed, came through 7-5, 6-3 and will face world number 11 Stefanos Tsitsipas in the last eight.

France's Cassandre Beaugrand won the Olympic women's triathlon on Wednesday after the event finally went ahead in a huge relief for organisers.

Cassandre Beaugrand took the women's gold ahead of Switzerland's Julie Derron and Britain's third-placed Beth Potter.

Women triathletes dived into the River Seine on Wednesday, marking the start of the race and providing huge relief for organisers after problems with water quality marred the run-up to the competition.