Claycourt king Rafael Nadal battled into the early hours as he reached the semi-finals of the Rio Open after beating Uruguayan Pablo Cuevas on Saturday.
Nadal, who will bid this season for a tenth Roland Garros crown, came through 4-6, 7-5, 6-0 in two hours and six minutes, after Cuevas was fastest out of the blocks in a contest lasting until 3:20 am (0520 GMT).
The late finish infuriated the world number three and defending champion, who complained of having to start a match at just after 1:00 am.
"I know it is not the fault of the tournament. It is the fault of the ATP wanting to change a match over (to a different court).
"If it were a Grand Slam where you get a day and a half (between matches), then okay," Nadal said afterwards, reflecting that he would have to be back in action again Saturday evening.
"I am going to go off to bed and we'll see if I have recovered" for a meeting with Italian world number 28 Fabio Fognini.
Fognini had kept Nadal waiting to enter the center court fray as he beat Argentine Federico Delbonis 6-4, 6-7 (10/12), 7-6 (11/9) in a three-hour marathon.
Nadal had seen off fellow Spaniard Pablo Carreno Busta and Brazilian Thomaz Bellucci to set up his meeting with Cuevas, but the Mallorcan's ring rustiness showed as he conceded the opening set in 44 minutes.
After trading early breaks, Cuevas broke in the ninth game and although the challenger spurned a triple set point he closed out the fourth opportunity on 44 minutes.
Cuevas sent down six aces but fourteen-time Grand Slam champion Nadal's wiliness and sheer doggedness reeled him in. Having leveled the contest Nadal wrapped matters up in taking the decider in just 25 minutes.
Also advancing was second seeded Spaniard David Ferrer who battled past Argentine Juan Monaco 6-3, 4-6, 6-2 in just over two hours on court at the Jockey Club in hot sunshine.
With temperatures hitting 42 degrees C (108 degrees F), both men made errors before Ferrer finally managed to find top gear as he gradually wore Monaco down, moving him around the court.
The ninth-ranked Spaniard broke Monaco twice and pocketed the opening set with an ace and the Argentine looked out for the count after dropping serve again at the outset in the second.
But the 30-year-old Monaco broke back in the sixth game as he leveled the contest.
That was as good as it got, however, for the South American veteran as Ferrer upped his game thereafter and finished his rival off with a huge serve.
Ferrer will now face Andreas Haider-Maurer in Saturday's semis after Haider-Maurer's 7-6 (7/4) 1-6, 6-4 win over Brazil's Joao Souza.
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