World number one Angelique Kerber shook off a slow start to defeat Italian veteran Francesca Schiavone 4-6, 6-0, 6-4 on Tuesday to reach the second round of the WTA tournament in Monterrey, Mexico.
Kerber, runner-up in Monterrey in 2013, was back at the tournament after a three-year absence.
The German, who regained the world number one ranking in March with American Serena Williams idled by injury, needed an hour and 40 minutes to get past Schiavone, the 36-year-old who has said this will be her last season on tour.
"It was not so easy to find the rhythm in the first set, because she played very well from the first ball and I was trying to find my game," Kerber said.
"I was a little bit tight today, but after the second set I was playing my game and moving good. I'm happy that I stayed positive."
Schiavone raced to a 3-0 lead in the opening set before Kerber found a way into the match, regaining a break before Schiavone broke again and served out the set.
Kerber dominated the second set, breaking Schiavone three times and dropping just three points on her own serve.
Kerber had won eight games in a row before Schiavone managed a hold in the third set.
But Kerber didn't face a break point in the final frame as she advanced to a second-round match against Luxembourg's Mandy Minella, a 7-6 (7/3), 6-3 winner over Bulgarian Elitsa Kostova.