Venus Williams, Federer Advance

By ESPN

Venus Williams defeated seventh-seeded Svetlana Kuznetsova 6-3, 7-6 (4) in a matchup of former Miami Open champions on Monday to reach the quarterfinals.

Williams fended off two set points to get into the tiebreaker, and then rallied from 4-1 down in the decider to win the match in two sets.

Williams will meet next top-seeded Angelique Kerber, who made it to the quarterfinals after beating Risa Ozaki 6-2, 6-2.

Caroline Wozniacki also advanced on Monday to the next round after Garbine Muguruza retired with a heat-related illness.

Wozniacki, the 12th seed, took the first set 7-6 over the sixth-seeded Muguruza. The Spaniard was tended to by doctors after the tiebreaker and decided she could not continue on a 77-degree, humid afternoon in South Florida. She said she began feeling a headache and stomach pain midway through the set, then experienced some dizziness.

"Kind of went more and more during the match," Muguruza said.

Wozniacki still has not dropped a set in the tournament and will next face Lucie Safarova in the quarterfinals. Safarova upset fourth-seeded Dominika Cibulkova 7-6, 6-1.

Earlier Monday, Karolina Pliskova also reached the quarterfinals, beating Czech Fed Cup teammate -- and occasional doubles partner -- Barbora Strycova 6-1, 6-4. Pliskova needed only 21 minutes to take the first set, winning 11 consecutive points in one stretch and 16 of 17 on her serve.

"I was expecting a tough battle," Pliskova said. "It was tricky in the end, but I'm glad I won."

Third-seeded Simona Halep dropped the first set before beating 14th-seeded Samantha Stosur. Other women's quarterfinal spots went to 10th-seeded Johanna Konta and 26th-seeded Mirjana Lucic-Baroni.

Federer Advances To Fourth Round

Roger Federer took a look around as he entered the stadium court at the Miami Open, already feeling the energy of the crowd.

He gave them quite the show.

Federer advanced to the fourth round at Key Biscayne on Monday, the No. 4 seed beating Juan Martin del Potro 6-3, 6-4. Federer, who was facing the 29th-seeded del Potro for the first time since 2013, never lost serve and improved to 15-1 this year.

He broke del Potro twice, once in each set, and that was all he needed.

"I feel like I earned it more," said Federer, the 2005 and 2006 champion at Key Biscayne. "I was more the aggressor. It was more my racket, and I like it that way."

The first break put him up 5-3 in the first set, and Federer then fought off four break points in the ensuing game before closing out the set.

Another break for a 3-2 lead in the second set, not long after del Potro got his oft-problematic left wrist taped on a changeover, put Federer in full control. Serving at 4-3, Federer faced a break point -- Argentine fans serenaded del Potro beforehand with "Ole! Ole! Ole!" -- but escaped when a serve return sailed long.

"I did my best," del Potro said. "He played well in the break-point moments and I think that was the only difference in the match."

It had the feel of a final, not a third-rounder on a Monday afternoon.

The stadium court, largely empty for the first two matches of the day, was filled -- with huge roars greeting both players as they entered for warm-ups, many fans wearing hats or shirts with Federer's "RF" logo, many others either donning Argentine soccer jerseys or carrying the nation's flag in support of del Potro.