Spanish third seed David Ferrer advanced to the quarter-finals of the WTA and ATP Miami Masters hardcourt event on Tuesday with a 6-4, 6-2 victory over Japan's 13th-seeded Kei Nishikori.
Ferrer won 84 percent of his first-serve points and 5-of-9 break chances to eliminate Nishikori and book a last eight-date against Austria's Jurgen Melzer, who defeated Spain's Albert Ramos 2-6, 6-3, 6-3.
Fifth-ranked Ferrer improved to 3-2 lifetime against Nishikori, having avenged a round-of-16 loss at last August's London Olympics by defeating Nishikori in the fourth round of this year's Australian Open.
Nishikori, ranked 15th, won their first meeting in the third round of the 2008 US Open while Ferrer first beat him in 2011 at Tokyo.
World number ones Novak Djokovic and Serena Williams both take the court in Tuesday's scheduled later matches.
US star Williams will face Chinese fifth seed Li Na in a quarter-final while Serbia's Djokovic will meet German 15th seed Tommy Haas in a fourth-round match.
Also in action later will be British second seed Andy Murray, who meets Italian 16th seed Andreas Seppi in quest of a spot in the final eight. Murray lost to Djokovic in last year's Miami final.