Eight-time champion Serena Williams has withdrawn from the Miami Open because of a knee injury. American Serena reached round three on Friday with victory over Sweden's Rebecca Peterson, only the seventh match she has completed in 2019.
The 23-time Grand Slam winner was set to face Wang Qiang in the last 32 but the Chinese 27-year-old now gets a bye.
World number one Naomi Osaka suffered a shock three-set defeat by Taiwan's Hsieh Su-wei in their third-round tie.
Serena said she was "disappointed to withdraw from the Miami Open due to a left knee injury".
The 37-year-old has now withdrawn from two consecutive WTA events, following her retirement from last week's tournament in Indian Wells with a viral illness.
Serena last claimed the Miami title in 2015, with her last Grand Slam win coming at the 2017 Australian Open, moving her one behind Margaret Court's record of 24 Grand Slam singles titles.
"I hope to be back next year to play at this one-of-a-kind tournament in front of the incredible fans here in Miami," she said.
Japan's Osaka, 21, who has won the past two Grand Slam tournaments - the 2018 US Open and the Australian Open in January - lost 4-6 7-6 (9-7) 6-3 to 33-year-old world number 27 Hsieh on Saturday.
"This was a very emotional win for me," said Hsieh, who will now face either Caroline Wozniacki or Monica Niculescu in the fourth round.
"Any time you beat one of the top players it is amazing."
World number two Petra Kvitova was tested by Croat Donna Vekic but won 6-4 3-6 6-4 to reach round four. The two-time Wimbledon champion and third seed had to fight for more than two hours against Vekic.
She will now meet France's Caroline Garcia in the fourth round. Garcia beat 15th seed Julia Gorges of Germany 6-0 7-5.
- Source: News websites