Top-seeded Juan Martin del Potro and Janko Tipsarevic won in straight sets on Friday to reach the semifinals of the Erste Bank Open.
Del Potro defeated Marinko Matosevic of Australia 6-2, 6-2 to line up a match against Gilles Muller of Luxembourg. Second-seeded Tipsarevic was leading 6-2, 4-2 when Aljaz Bedene retired with a left thigh injury.
Tipsarevic will play Grega Zemlja of Slovenia, who scored 14 straight points to close out a 6-4, 4-6, 6-2 win over Tommy Haas.
Del Potro played his second match since returning from a right wrist injury that sidelined him for more than a month.
''I feel confident with my shots, but I need to improve a little bit,'' the eighth-ranked Argentine said. ''I would love to be in the final, but I need to serve well and find a way to break (Muller's) serve.''
Del Potro saved a break point in his opening service game against Matosevic and two more while serving for victory, but was in control throughout the match...