Stakhovsky grabbed tennis world attention when he upset Roger Federer in the second round at Wimbledon but Monday's 6-4, 6-3 victory over seventh-seeded Joao Sousa is just his second win in 10 ATP matches since then.
He won with a solid service game, having six aces and no double faults while winning 68 percent of the points on serve. He saved two of the three break opportunities for Sousa.
No. 6-seeded Horacio Zeballos rebounded from a slow start and posted a 1-6, 6-3, 6-4 win over Ricardas Berankis. Zeballos dropped two of three break points he saw in the first set but his comeback was fueled when he saved eight break points in the second set and five in the third without dropping his serve.
Also Monday, wild-card entrant Karen Khachanov defeated Albert Ramos 6-2, 3-6, 6-4 and Edouard Roger-Vasselin topped Jiri Vesely 6-3, 6-7 (3-7), 6-3.