Novak Djokovic and Maria Sharapova both survived unscathed, but the Sony Open lost two other Grand Slam champions on Friday, when Victoria Azarenka and Juan Martin del Potro exited the Miami tournament.
Azarenka withdrew from her opening match because of an ankle injury she suffered playing at Indian Wells last week.
“I’m very disappointed ... But I have to take my health into consideration,” said Azarenka, who won the Australian Open in January, but has struggled with injuries since.
“I tried everything I could, but couldn’t make it. It’s an unfortunate part of our job,” she said.
Azarenka’s withdrawal proved an unexpected bonus for US teenager Lauren Davis, who failed to qualify for the tournament.
She was given a “lucky loser” pass into the event when Azarenka pulled out then saved three match points in defeating Madison Keys 6-1, 5-7, 7-6.
“I just hoped and I wished and I prayed that I would get in,” Davis said. “I was just so happy. I didn’t care if I won or lost. I just was so grateful for the opportunity to play.”
Former US Open champion Del Potro, ranked No. 7 in the world, suffered a surprise 7-6, 6-1 loss to Germany’s Tobias Kamke.
The towering Argentine had two set points in the opening set, but lost his way just a week after making the men’s final at Indian Wells.
“He didn’t play obviously his best tennis,” Kamke said.
“But still, I think I did a good job and I’m pretty satisfied with that,” he added.
There were no other major casualties amongst the top seeds, with Djokovic and Sharapova both winning in straight sets.
Sharapova romped to a 6-2, 6-0 win over Canada’s Eugenie Bouchard, while Djokovic, playing in the late night match, cruised to a 6-1, 6-0 victory over Lukas Rosol.
Only Spain’s David Ferrer, the men’s third seed, had an easier time. He won in a walkover when Dmitry Tursunov pulled out.