Rafael Nadal was forced to retire against Damir Dzumhur on a hot and muggy Saturday at the Miami Open presented by Itau. Dzumhur, No. 94 in the Emirates ATP Rankings, was up 2-6, 6-4, 3-0 in the second-round match when the Spaniard was unable to continue. Dzumhur had never beaten a Top-10 player in five previous attempts.

“Everything was fine until the end of the first set,” Nadal said. “Then I started to feel dizzy, not very good. It was getting worse and worse. Finally, in the second set, I realised that I could not keep playing.

“I wanted to finish the match, but I seriously could not. It was tough, because I felt I was playing well. I had good practices after a great week in Indian Wells. I stopped because I was concerned for my health, and I could not finish the match the way I was feeling.”

Despite its final outcome, the match did not start auspiciously for Dzumhur. The Bosnian faced 12 break points in losing the one-sided opening set, and was the first to request the trainer. The 23 year old was visibly affected by Miami’s heat and humidity, but soldiered on after receiving assistance during the changeover.

Nadal was unable to capitalise on Dzumhur’s discomfort. After breezing through his service games in the opening set, the left-hander won only 50 per cent of first-serve points the rest of the way (11/22) and was broken four times in as many opportunities in the last two sets. An ailing Nadal called for the trainer twice before retiring after an hour and 50 minutes. The Spaniard, a four-time finalist in Miami, will have to wait another year to capture the elusive title.

“It’s definitely not the way I wanted to finish,” Dzumhur said. “It was really tough to play today. I also felt tired, heavy, and in some moments dizzy on the court. In the first set we played a very long second game. After that game I felt I could not run that well.

“Between the first and second sets, I calle a medical time-out. I was really thinking about retirement, but just said to myself, ‘I'm playing Rafa. I don’t have a chance to play these guys every day. I want to enjoy this moment.’ So I tried to continue."

In the third round, Dzumhur will face Mikhail Kukushkin, who advanced when Thomaz Bellucci retired at 7-5, 3-6. The Kazakh, No. 90 in the Emirates ATP Rankings, is into the third round in Miami for the first time. His previous third-round appearance in an ATP World Tour Masters 1000 event dates back to Indian Wells 2014 (l. to Lopez).