MIAMI (AFP) - Third-seeded Maria Sharapova battled to a 6-4, 6-2 victory over fellow Russian Elena Vesnina on Sunday to book her fourth-round berth at the Miami ATP Masters and WTA hardcourt tournament.
Sharapova, who won the title last week at Indian Wells, will take on Czech Klara Zakopalova for a quarter-final berth on Monday.
The Russian star has never won the Miami title, although she's reached the final four times.
Steffi Graf and Kim Clijsters are the only women to win both Indian Wells and Miami in the same year - Graf in 1994 and 1996 and Clijsters in 2005.
In hot, humid, windy weather, Vesnina started strong, breaking Sharapova to take a 3-1 lead in the opening set.
Sharapova responded by winning 11 of the next 14 games to secure a straight-sets victory.
"Isn't it amazing what happens when you're down? You just switch on," Sharapova said with smile.
"I think it was a matter of patience. From the warmup the conditions are not great. You're facing an opponent that is very capable of playing good tennis.
"Maybe her ranking is not where she wants it to be right now, but she's beaten me before.
"In situations like this where it's tough and it's hot, it kind of levels out the game a little bit as well ... you have to be a bit more patient. That was really important today." After leveling the first set at 3-3, Sharapova gained the decisive break in the seventh game. She battled back from 0-40 down in the next game to hold serve and wrapped up the first set in just over an hour.
Sharapova said Zakopalova would be a dangerous opponent.
Sharapova leads their head-to-head 4-1, the Czech winning their first encounter when Sharapova was 15.
Sharapova needed three sets to get past the Czech veteran in the fourth round of the French Open last year, en route to completing a career Grand Slam with her Roland Garros triumph.
The Russian beat Zakopalova again in Doha this year.
"She's a tricky one because she's a grinder," Sharapova said. "She gets so many balls back and makes you hit a lot. You can never underestimate her game."