Monaco, playing the day's final match, defeated qualifier Henri Laaksonen 6-4, 6-2. Monaco had a pair of breaks in each set and only dropped his serve once. He won about two-thirds of the points on serve.
Albert Ramos ousted Robredo 6-3, 6-4 without facing a break point. Ramos lost a mere nine points over 10 games serving, taking 82 percent of those points. He also converted two of his five break chances to gain a spot in the quarterfinals.
Fifth-seeded Grigor Dimitrov got by Filippo Volandri 2-6, 6-1, 6-4. He lost his serve twice in the first set but only saw two break points the rest of the way.
The other second-round match Wednesday saw Carlos Berlocq beat Blaz Kavcic 7-5, 6-3. He also served well, losing his serve once on the day.
Monaco and Dimitrov are matched against each other in the quarterfinals while Ramos and Berlocq will also meet in the next round.
Celebrity Families of 2014 [PHOTOS]