South African Kevin Anderson beat Ecuador's Emilio Gomez in straight sets Wednesday to advance to the quarterfinals at the inaugural Colombia Open tennis event.

Anderson, seeded second, earned a 6-3, 7-6 (7-2) triumph on the hardcourts at Centro de Alto Rendimiento. Anderson's next opponent will be sixth-seeded Colombian crowd favorite Santiago Giraldo. He reached the quarterfinals with a 3-6, 6-3, 6-4 victory over Aussie qualifier Chris Guccione.

An upset came when 6-foot-10 Croat Ivo Karlovic took out third-seeded Dutchman Igor Sijsling, 6-3, 7-6 (16-14). The towering Karlovic swatted 24 aces, compared to only nine for the Sijsling, and the Croat recorded the only break of the match in the opening set.

Also Wednesday, fifth-seeded Frenchman Adrian Mannarino defeated Victor Estrella Burgos of the Dominican Republic, 6-1, 6-2. Mannarino will play Karlovic in the quarterfinals.

The top half of the draw plays its second-round matches Thursday, including top seed Janko Tipsarevic of Serbia. He'll face Belgium's Ruben Bemelmans.

The winner of this $638,000 tournament will collect $115,200.