On Monday, the 33-year-old Spaniard, only tested so far by second-round opponent Nick Kyrgios, eased to a 6-2, 6-2, 6-2, win, BBC Sport reported.
Seven-time Wimbledon champion Serena Williams, meanwhile, reached the quarterfinals with a dominant display against Spain's Carla Suarez Navarro.
The American 11th seed, 37, raced to a 6-2, 6-2 victory against the 30-year-old world number 31.
Williams will play compatriot Alison Riske in the last eight after she upset world number one Ashleigh Barty.
Ukrainian eighth-seed Elina Svitolina also moved into the last eight with a 6-4, 6-2 win against Petra Martic.
"I have more matches this week than in the past five months, but it is good," said Williams, who is through to the second round of the mixed doubles with Britain's Andy Murray.
"I know I can play and now that I feel better physically I almost feel a relief. I still want it or I wouldn't be here."
Williams took control from the outset, breaking Suarez Navarro's serve in the first game then broke again to go 5-2 up.
But shortly before that Williams, who played in her first Grand Slam in 1998, had to be reminded of the rules by the umpire as she reached over the net to hit a volley.
The 23-time major winner told the umpire "I thought it was allowed" after the point was overruled, but was ultimately undisturbed as she claimed the first set in 31 minutes.
Williams made an equally commanding start to the second set as she broke Suarez Navarro in her first two service games, but the four-time Olympic champion then dipped momentarily as she lost her serve to love.
Suarez Navarro has never won more than three games in a set against the American though, and Williams ensured that record continued as she broke for a third time then held serve to close out the match in one hour and four minutes.