Indian Wells champions Carlos Alcaraz and Elena Rybakina stayed on course to complete the 'Sunshine Double' at the Miami Open but Stefanos Tsitsipas was sent packing by Karen Khachanov.
World number one Alcaraz beat Tommy Paul 6-4 6-4 in the fourth round, while Rybakina notched up her 12th straight win with a 6-3 6-0 thrashing of Martina Trevisan to reach the semi-finals.
Alcaraz is now three wins away from securing the 'Sunshine Double' after his victory at Indian Wells last week - a triumph that would see him retain the world number one ranking ahead of Novak Djokovic.
In the quarter-finals the Spaniard will play another American in Taylor Fritz, who eased past Denmark's Holger Rune 6-3 6-4 on Tuesday.
At the Grandstand, Italian 10th seed Jannik Sinner breezed past sixth seed Andrey Rublev, firing off more than two dozen winners to win 6-2 6-4.
Khachanov, seeded 14th, earned his first win over Tsitsipas in seven meetings, taking down the Greek world number three 7-6(4) 6-4 in the fourth round to end a 23-match winless run against a top-10 opponent.
Tsitsipas, who got a first-round bye and second-round walkover, beat Cristian Garin in his Miami Opener on Monday but never found his best level against Khachanov, who controlled the match by winning almost 90% of his first-serve points.
Khachanov will face Lorenzo Sonego of Italy or Argentina's Francisco Cerundolo in the quarter-finals.
Wimbledon champion Rybakina has been in rare form this year after reaching the final of the Australian Open and was hardly troubled as she extended her winning streak.
The 10th seed deployed her clean groundstrokes and feasted on Italian 25th seed Trevisan's soft second serve in the tight first set.
But it was all Rybakina in the second, the powerful and precise Kazakh pounding an unreturnable serve on match point to set up a last-four meeting with Jessica Pegula or Anastasia Potapova, who play later on Tuesday.
"Maybe I'm moving not as good as I was moving in Indian Wells but overall I think that I'm trying to keep that level from Indian Wells," she said.
"There are a lot of ups-and-downs, but I think overall it's not bad."