The new site for the Miami Open suddenly is missing a lot of star power.
Serena Williams withdrew, blaming a previously undisclosed left knee injury. Less than two hours later, top-ranked Naomi Osaka lost in the third round to tour veteran Hsieh Su-Wei of Taiwan, 4-6, 7-6 (4), 6-3.
Osaka's departure matched the earliest ever in the tournament by a top-seeded woman and jeopardized her No. 1 ranking, depending on results next week.
"I feel like I've dealt with the stress of people asking me do I have pressure because I have the No. 1 next to my name," Osaka said. "I thought I was doing fine with that, but I guess I'm not."
"I am disappointed to withdraw," she said in a statement. "It was an amazing experience to play at Hard Rock Stadium this year, and I would like to thank the Miami Open for putting on an amazing event. 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."
"It was a great atmosphere," Federer said. "It was electric. I think that's why I played so well at the end."
"I know it's depressing," she said. "I was thinking about it right after I lost."