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.