World number one Rafael Nadal set a new record of winning 50 consecutive sets on a single surface by beating Argentine Diego Schwartzman 6-3, 6-4 on Thursday to reach the Madrid Open quarter-finals.
The Mallorcan surpassed John McEnroe's previous record of 49 consecutive sets on carpet which had stood since 1984 by seeing off 13th seed Schwartzman and claiming a 21st consecutive win on clay.
Nadal will face Austrian Dominic Thiem in the last eight on Friday in pursuit of a sixth Madrid Open title after beginning the claycourt season by winning an 11th Monte Carlo Masters and lifting the Barcelona Open trophy for the 11th time.
Nadal said he was unaware of the record.
"These moments I don't go out there and think about these kind of things. I just think about my opponent, what I have to do to keep on going. That's all," Nadal told a news conference.
"When my career is over, these are things that are going to be there for always. They are big records. It's difficult to be able to win 50 sets in a row. But I've done it. Let's not talk about that any more and let's continue on what we have ahead."
World number six Juan Martin del Potro crashed out of the tournament after Serbia's Dusan Lajovic came back from a set down to beat the Argentine 3-6, 6-4, 7-6(6) in the third round.
Del Potro looked in complete control as he converted two break-point opportunities to take the opening set but Lajovic, ranked 95th in the world, dug deep to stay in the contest.
A break midway through the second set was enough for Lajovic to force a decider before he wrapped up his first career victory over a top-10 opponent in the tiebreak.
In the quarter-finals, Lajovic will meet South Africa's Kevin Anderson who overcame German Philipp Kohlschreiber 6-3, 7-6(7).
Britain's Kyle Edmund followed up his surprise win over Novak Djokovic by defeating world number 10 David Goffin to reach the last eight of an ATP Masters 1000 event for the first time in his career.
The 23-year-old broke his Belgian opponent's serve twice in the opening set and once in the second, to seal a 6-3, 6-3 victory in an hour and 12 minutes.
Edmund will next face Canadian teenager Denis Shapovalov, who achieved a 6-4, 6-4 win over compatriot Milos Raonic.
American John Isner also advanced to the quarter-finals after overcoming Uruguayan Pablo Cuevas in a tight match 7-6(9), 7-6(3), 7-6(4). He will play German Alexander Zverev, who beat Argentine Leonardo Mayer 6-4, 6-2.
Pliskova ends Halep's Madrid hat-trick bid
World number one Simona Halep's Madrid Open hat-trick hopes ended as she was overpowered 6-4, 6-3 in the quarter-finals by inspired Czech Karolina Pliskova on Thursday.
Halep, who has won the tournament for the last two years, had looked imperious on her way to the last eight, dropping nine games in three matches including Wednesday's victory over Pliskova's twin sister Kristyna.
But her winning streak in the Spanish capital ended at 15 matches as her 26-year-old opponent continued her impressive form on the red clay having won the Stuttgart title last month.
It was sixth seed Pliskova's first claycourt victory over Halep and it was the kind of authoritative performance that will turn a few heads with the French Open looming.
Pliskova will play fellow Czech Petra Kvitova in the semi-finals after the 10th seed beat Russian Daria Kasatkina 6-4, 6-0.
Dutchwoman Kiki Bertens continued her impressive week as she backed up a third-round win over world number two Caroline Wozniacki to beat Maria Sharapova and advance to the last four.
Unseeded Bertens, who reached the French Open semis two years ago, recovered from losing the first set to win 4-6, 6-2, 6-3 and set up a semi-final with Caroline Garcia who eased past local hopeful Carla Suarez Navarro.
Bertens' win over Wozniacki meant Halep will stay as world number one for at least another week, but the Romanian had no answer to Pliskova on centre court.
Pliskova broke for a 4-3 lead in the opening set and although Halep saved two set points serving at 3-5 Pliskova closed out the opener with a love hold.
Romanian Halep's error-count was surprisingly high, and she found herself under pressure early in the second set as Pliskova pounced to break in the third game.
Halep could make little impression on Pliskova's powerful serving and she buckled at 3-5, dropping serve again to bow out.
She quickly shrugged off the loss, however, saying she would now focus on Rome next week before turning her thoughts to another attempt to land a first grand slam title.
"I'm not stressing myself about the (ranking) points," said Halep, who also has a lot of ranking points to defend in Rome having reached last year's final. "I'm not stressing myself about this busy schedule."
"I just want to enjoy it. I'm looking forward already to start the next tournament. There is no pressure. I feel like it's an opportunity to play my best tennis."
"Maybe I didn't play my best game, but maybe she didn't let me play my best game. She was really good today."