Serena Williams set up a Wimbledon third-round tie against Britain's Heather Watson after overcoming Timea Babos 6-4 6-1.
The five-time SW19 champion was tested in the opening set by the big-serving world number 93 from Hungary, but by the second she was in full control and emerged an emphatic winner on Centre Court.
Watson, the British number one, now awaits Williams as she seeks to add the Wimbledon crown to the Australian and French Open titles she has already claimed this year.
In one of the day's biggest surprises, 158th-ranked American qualifier Bethanie Mattek-Sands upset seventh-seeded Ana Ivanovic 6-3, 6-4. Mattek-Sands, who was out for six months last year with a left hip injury, had 32 winners, more than twice the number for Ivanovic. In other women's play, 2004 champion and fourth-seeded Maria Sharapova advanced by beating Dutch qualifier Richel Hogenkamp 6-3, 6-1 on Court 2. The Russian had eight double-faults but also 23 winners.