Spain's world number one Carlos Alcaraz defeated American Tommy Paul in straight sets to reach the quarter-finals of the Miami Open.
The 19-year-old US Open champion won 6-4 6-4 to extend his winning streak to nine matches.
Alcaraz must retain the Miami title in order to stay top of the ATP rankings.
He will play another American, Taylor Fritz, in the last eight after the ninth seed beat Denmark's Holger Rune 6-3 6-4.
Victory in the tournament would also see him achieve the rare 'Sunshine Double' following his title win at Indian Wells earlier in March.
In the women's draw, Wimbledon champion Elena Rybakina progressed to the last four with a 6-3 6-0 win against Italy's Martina Trevisan.
The Kazakh 10th seed could also achieve the 'Sunshine Double' and takes a 12-match unbeaten run into her semi-final with Jessica Pegula.
The American third seed had to come back from a set down to beat Russian Anastasia Potapova 4-6 6-3 7-6 (7-2), saving two match points in an epic that finished at 1:30am.
Daniil Medvedev's fourth-round match with Quentyn Halys started after midnight but the men's fourth seed swept aside the Frenchman 6-4 6-2 in just over an hour.
"I thought it was going to be cancelled," said Medvedev. "I'm really happy I was able to play not so bad, I'm usually asleep at midnight."
In the quarter-finals the Russian will face American qualifier Christopher Eubanks, who claimed another notable scalp by beating France's Adrian Mannarino 7-6 (7-2) 7-6 (7-5).
The game was delayed by rain for about four hours with Eubanks, ranked 119th in the world, 4-2 up in the first set.
Eubanks claimed his first win at a major at last year's 2022 US Open
After play resumed, Mannarino forced a tie-break before losing out to the big-serving American, who prevailed in another tie-break in the second set to reach a Masters 1000 quarter-final for the first time in his career.
Having come through the qualifiers in Miami, the 26-year-old has won six straight games and will enter the world's top 100 for the first time next week, with actor Jamie Foxx among those to congratulate him this week.
"Blood, sweat and tears and true hard work has paid off for my good friend," Foxx wrote on social media.
Elsewhere, Russian Karen Khachanov recorded his first victory over second seed Stefanos Tsitsipas, beating the Greek 7-6 (7-4) 6-4.
Seeded 14th, Khachanov will now play the number 25 seed, Argentina's Francisco Cerundolo, who beat Italy's Lorenzo Sonego 3-6 6-3 6-2.
Sonego's compatriot 10th seed Jannik Sinner defeated Russian Andrey Rublev 6-2 6-4 and will play Finland's Emil Ruusuvuori in the last eight.