MIAMI GARDENS, Fla. -- The new site for the Miami Open suddenly is missing a lot of star power.
Top-ranked Naomi Osaka lost Saturday to tour veteran Hsieh Su-Wei of Taiwan in the third round of the Miami Open 4-6, 7-6 (4), 6-3.
The upset came shortly after eight-time champion Serena Williams withdrew, blaming a left knee injury.
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. It was the first time in 64 matches that Osaka lost after winning the first set.
"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.''
Roger Federer briefly seemed headed for the exit but instead advanced to the third round by rallying past qualifier Radu Albot 4-6, 7-5, 6-3.
"Radu put me through the ringer,'' Federer said.
No. 2-seeded Alexander Zverev double-faulted 12 times and lost to wild card David Ferrer 2-6, 7-5, 6-3.
Federer, a three-time champion, lost serve only once -- in the first game -- but was on the ropes until he swept the final three games, to the relief of an enthusiastic stadium crowd.
"It was a great atmosphere,'' Federer said of playing at the Miami Dolphins' Hard Rock Stadium, the tournament's new center court after the event moved this year from Key Biscayne. "It was electric. I think that's why I played so well at the end.''
While attendance in the stadium continued to be spotty, outer courts were jammed, and the day session drew a tournament-record 32,831 spectators.
The 33-year-old Hsieh closed out match point against Osaka with a forehand volley winner, and then began to cry as the crowd applauded her performance. She turned pro in 2001 and has three other victories over top-five players, including an upset of No. 1 Simona Halep at Wimbledon last year.
With two-handed groundstrokes from both sides, Hsieh was the steadier player from the baseline against Osaka, who has won the past two Grand Slam tournaments.
Osaka smiled when reminded it was the first time in 64 matches she lost after winning the first set.
"I know -- it's depressing,'' the 21-year-old said. "I was thinking about it right after I lost.''
Williams was next scheduled to play No. 18-seeded Qiang Wang, who advanced along with Hsieh to the fourth round.
Other seeded losers on the men's side included No. 10 Karen Khachanov, No. 21 Diego Schwartzman, No. 26 Guido Pella, No. 30 Stan Wawrinka and No. 31 Steve Johnson. In a game of inches, the 5-foot-6 Schwartzman lost to 6-foot-11 Reilly Opelka 6-4, 3-6, 6-4.
Information from The Associated Press was used in this report.