The 6-foot-6 Cilic, the tournament's top seed, thrilled his countryman in Zagreb, Croatia, by improving to 14-1 this season, and avenging a 6-4, 6-3 loss to Melzer at the Bank Austria Tennis Trophy final in Vienna last October.
"Melzer was a really tough opponent," Cilic admitted. "Winning the first set was a big relief, and the second set was much, much better from my side also."
Cilic tries to win this event a second straight year Sunday against unseeded Michael Berrer of Germany, a 7-6 (10-8), 7-5 winner over fellow German Philipp Petzschner in Saturday's other semifinal.
Sunday's Cilic-Berrer winner receives a $95,500 champion's check.
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