Elena Rybakina recovered from a poor start to avoid a first-round exit against American Shelby Rogers.
The defending Wimbledon champion recovered from a double fault, to win 4-6 6-1 6-2.
Reports of her illness were given credence in her build-up, as she struggled for intensity and momentum against the world number 49 at the start but redeemed herself thanks to a late rally.
A defeat would have made Rybakina, the first women’s defending champion since 1994 to lose at this stage.
Later, Tunisia’s Ons Jabeur beat Poland’s Magdalena Frech 6-3 6-3.
For her effort, the defending champion will play France’s Alize Cornet or Japan’s Nao Hibino in the second round. If Rybakina successfully defends of her title, she will become the first woman since Serena Williams in 2016 to defend the women’s singles title at Wimbledon.
