Second seed Aryna Sabalenka fought back to avoid an upset and beat France's Varvara Gracheva to secure a place in the Wimbledon third round.
The Belarusian, one of the favourites for the title, seemed out of sorts on a stiflingly hot Court One against the world number 41.
She hit five double faults in the first set but regrouped to win 2-6 7-5 6-2.
Top seed Iga Swiatek and last year's runner-up Ons Jabeur are both in action later on Friday.
Australian Open champion Sabalenka looked out of sorts in the opening exchanges against Gracheva, making 16 unforced errors and giving away her serve three times.