Novak Djokovic was chasing a shot in his forehand corner when his left foot gave way and he tumbled to the court, landing on his left side as his racket went flying.
He lost the point, the game and his serve, making it 4-all in the first set. But the collision with the concrete gave his game a needed jolt, and he quickly rose to pull away and beat Joao Sousa 6-4, 6-1 on Sunday in the third round at the Miami Open.
In the first game after he fell, Djokovic cracked several forehands more forceful than what he had previously offered. He broke for a 5-4 lead and lost only 11 points in the final eight games.
Djokovic said he slipped on a wet spot and wasn't concerned that he had hurt himself. But he was worried about beating Sousa.
''That first set went down to a few points,'' Djokovic said. ''After that it was quite a good performance. He made me push myself harder in the second set.''
Seeded No. 1, Djokovic is bidding for his sixth Key Biscayne championship, which would tie Andre Agassi's men's record. Serena Williams is seeking her ninth title.
Lucky loser Horacio Zeballos of Argentina joined Djokovic in the round of 16 by saving a match point and beating Fernandez Verdasco 1-6, 6-4, 7-6 (4).
Zeballos' wife, Sofia, is back in Argentina monitoring his matches while awaiting the birth of their child due April 10.
''During the third set, all of a sudden I started thinking, 'I hope she's not nervous,''' Zeballos said in Spanish. ''It was crazy for me to be having those thoughts during the match. I am having a great time here, but I also want the baby to be born already and experience that moment of becoming a father. Hoping she can hang on a few more days.''
Zeballos said he will pull out of the tournament if his child is born while he's still contending. He lost in qualifying but made the draw when Roger Federer withdrew because of a stomach virus.
On the women's side, two-time champion Victoria Azarenka overcame five double-faults and held every service game to beat qualifier Magda Linette 6-3, 6-0. Azarenka, seeded 13th, moved into the fourth round and is bidding to become only the third woman to win Indian Wells and Miami back to back.
Floridian Madison Keys, seeded No. 22, reached the round of 16 for the first time in seven tournament appearances by beating No. 9 Roberta Vinci 6-4, 6-4. Keys won 19 of 21 points at the net.
In other men's play, No. 7 Tomas Berdych erased all 10 break points he faced and defeated American Steve Johnson 6-3, 6-7 (6), 6-3. Johnson, seeded 31st, fell to 0-13 against top-10 opponents.
No. 14 Dominic Thiem advanced to the fourth round against Djokovic by beating qualifier Yoshihito Nishioka 6-2, 6-2. Djokovic ranks the 22-year-old Thiem as one of his favorite players to watch.
''He's a young player who has a lot of potential and a nice variety in his game,'' Djokovic said.
It was hot and humid for a second day in a row, and Djokovic was fortunate to play in the evening shadows. He endured plenty of strenuous points in the first set, but Sousa then faded with a flurry of errors.
Seeded 33rd, Sousa has lost 19 matches in a row when playing top-10 opponents.
''Joao really played well in the beginning,'' Djokovic said. ''He wanted to take his chances; there's not much to lose. In these cases it can be dangerous if you're not hitting the ball well, but I rose to the occasion.''
With three of the five highest-seeded men already departed, Djokovic is a heavy favorite for another title. He improved to 24-1 this year and 38-5 lifetime at Key Biscayne.
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