Ferrer became the only seeded player to reach the UNICEF quarterfinals with a 6-3, 6-1 win over Leonardo Mayer. The 60-minute match saw Ferrer convert all four of his break opportunities.
He lost just six points in eight games serving. Ferrer won 16-of-18 points on serve in the first set.
Tatsuma Ito ran over third-seeded Jurgen Melzer 6-2, 6-2 in 57 minutes. Ito had a pair of breaks in each set and supported that by winning more than three-quarters of the points on serve.
Benoit Paire got by eighth-seeded Lukasz Kubot 6-3, 0-6, 6-4. Paire won two fewer -- 78-80 -- points overall, but that was because Kubot dominated the second set.
Thursday's quarterfinal schedule has Ferrer taking on Sijsling, Ito meeting Paire, Roger-Vasselin playing Petzschner and Muller going against Malisse.