Serena Williams’ 20-match win streak at Key Biscayne ends with loss to Svetlana Kuznetsova

Serena Williams’ 20-match winning streak at Key Biscayne ended Monday with a 6-7 (3), 6-1, 6-2 loss to Svetlana Kuznetsova in the fourth round of the Miami Open.

Williams was bidding for her ninth title in the event and her fourth in a row. But after a grueling first set that lasted nearly an hour, the No. 1-seeded Williams faded on a sweltering afternoon.

The No. 15-seeded Kuznetsova won with defense, extending points until Williams would make a mistake. The Russian finished with only 18 unforced errors to 55 for Williams.

In addition, Williams’ serve was uncharacteristically unreliable. She hit 13 aces but also had nine double faults and was broken six times.

On the men’s side, No. 2 seed Andy Murray lost the final five games and was beaten by No. 26 Grigor Dimitrov, 6-7 (1), 6-4, 6-3, in the third round.

Murray, who won the Key Biscayne title in 2009 and 2013, committed 22 unforced errors in the final set and 55 total. He was broken six times, including in his final three service games.

Murray’s elimination leaves the tournament without four of the five top-seeded men. Among them only No. 1 Novak Djokovic reached the round of 16.

This is the first time Williams hasn’t reached the Key Biscayne quarterfinals since 2000, when she lost in the fourth round to Jennifer Capriati.

“I did the best I could,” Williams said during a postmatch news conference that lasted less than three minutes before she cut it off. “I can’t win every match. These players come out and play me like they’ve never played before in their lives. I have to be 300% every day.”

Williams, 34, will retain the No. 1 ranking, but she hasn’t won a tournament since earning her 69th title at Cincinnati in August.

Also sidelined were No. 3-seeded Agnieszka Radwanska and No. 4 Garbine Muguruza. Two-time champion Victoria Azarenka, seeded 13th, committed only 12 unforced errors and defeated Muguruza, 7-6 (6), 7-6 (4). No. 19 Timea Bacsinszky eliminated Radwanska, 2-6, 6-4, 6-2.