Olympics Rio 2016: Watson and Edmund through, Inglot and Fleming crash out

Watson's was perhaps the most impressive performance. She had a tough test against Shuai Peng of China, and failed to serve out the second set, dropping it on a tie-break.

But she came back in the decider, and despite some nerves on her service again, including a double fault in the final game, she eventually rounded it off to win 6-4 6-7 6-3.

Peng, ranked 264 but in the tournament on a protected ranking after injury, has only won one tour-level match all season while Watson was on a four-match losing streak.

"It was a toughie," said Watson, who lost in the second round on her Olympic debut in London. "I didn't play my best. I don't think it was the prettiest of matches but it was one of those winning ugly ones and in the third set I think it was a battle of the fittest and I actually felt great, so I'm really pleased with that."

The doubles pairing of Inglot and Fleming had earlier lost 6-3 6-0 to Santiago Gonzalez and Miguel-Angel Reyes-Varela of Mexico.

Kyle Edmund had a slightly more successful start in the men's singles, beating Australia's Jordan Thompson 6-4 6-2.

Johanna Konta will also be in action later on Day One of the Games, partnering Watson in the women's doubles.