Rafael Nadal is forced to retire from match in Miami Open

Rafael Nadal faded in the subtropical heat and retired after falling behind in the third set of his opening match at the Miami Open against Bosnia’s Damir Dzumhur.

The No. 5-seeded Nadal trailed 2-6, 6-4, 3-0 when he called it quits after losing a point to fall behind 30-15. He had earlier consulted with a trainer at his chair between games three times, and had his blood pressure checked.

The match lasted less than two hours, but the weather was sunny and humid, with a temperature approaching 90 degrees and even higher on the stadium hardcourt.

Eight-time champion Serena Williams avoided the upset bug and seemed unfazed by the weather. The South Floridian earned her 20th consecutive victory at Key Biscayne and reached the fourth round by beating Zarina Diyas, 7-5, 6-3.

“I live down the street,,” she said. “Even though it was a little humid, I’m used to it and I love this weather.”

Nadal, a 14-time Grand Slam event champion, hasn’t won a tournament since August. But it had been 443 matches since he retired — in the 2010 Australian Open quarterfinals against Andy Murray.

“It was getting worse and worse and worse,” the Spaniard said. “I get a little bit scared — too dizzy. I felt I was not safe, so I decided to go. I wanted to finish the match, but I seriously couldn’t.”

Nadal’s departure left the draw without three of the five highest-seeded men. No. 4 Stan Wawrinka lost to Andrey Kuznetsov and No. 3 Roger Federer withdrew Friday because of a stomach virus.

No. 13 John Isner double-faulted on his final two service points and lost to qualifier Tim Smyczek, 6-2, 2-6, 7-6 (5).

No. 6 Kei Nishikori defeated qualifier Pierre-Hughes Herbert, 6-2, 7-6 (4). No. 12 Milos Raonic, the runner-up at Indian Wells this month, beat Denis Kudla, 7-6 (4), 6-4.

On the women’s side, No. 8 Petra Kvitova lost to No. 30 Ekaterina Makarova, 6-4, 6-4. No. 3 Agnieszka Radwanska, the 2012 champion, eliminated Madison Brengle, 6-3, 6-2.