(Reuters) - Japan's world number one Naomi Osaka was sent spinning to a crushing loss when Taiwan's 27th seeded Hsieh Su-wei defeated her in three absorbing sets at the Miami Open on Saturday.
Hsieh came from a set down to prevail 4-6 7-6(4) 6-3 as her unorthodox style frustrated and finally wore down the U.S. and Australian Open champion.
The stunning upset came after the tournament had earlier lost its eight-times champion Serena Williams.
The great American player withdrew with a left knee injury, the second consecutive WTA event which she has been forced to abandon following her retirement from last week's tournament in Indian Wells with a viral illness.
Earlier, world number two Petra Kvitova was extended to three sets before the Czech outlasted Croatia's Donna Vekic.
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 knocked out 15th seed Julia Goerges, of Germany, 6-0 7-5.
(Reporting by Gene Cherry in Raleigh, North Carolina; Editing by Ian Chadband)