(Reuters) - World number two Petra Kvitova was extended to three sets before the Czech overcame Croatia's Donna Vekic in the third round of the Miami Open on Saturday.
Two-time Wimbledon champion Kvitova finally prevailed 6-4 3-6 6-4 in the clash between two heavy hitters but had to fight to earn her triumph after more than two and a half hours.
Kvitova, the third seed, will meet France's Caroline Garcia in the fourth round. Garcia had earlier knocked out 15th seed Julia Goerges, of Germany, 6-0 7-5.
World number one Naomi Osaka of Japan was playing Taiwan's Hsieh Su-wei later.
(Reporting by Gene Cherry in Raleigh, North Carolina; Editing by Ian Chadband)
