The 6-foot-10 inch Karlovic, known for power tennis, needed only 54 minutes to dismantle his opponent and improve his record to 6-3 this season. He hit 15 aces and converted four of 10 break point chances against his 98th-ranked foe.
In other results, doubles specialist Michael Llodra downed Netherlands native Robin Haase 7-6 (7-5), 7-6 (7-5) to increase his singles record this season to 12-3; Sweden's Robin Soderling beat Italian Andreas Seppi 6-3, 6-2; and Frenchman Gilles Simon beat Russian Teimuraz Gabashvili 6-3, 6-2.
Saturday's semifinal matchups are Simon-Soderling and Karlovic-Llodra.
Sunday's champion will pocket a winner's check of $250,000.