Marin Cilic faces the first real test of his title defense.

Cilic has made serene progress to the quarter-finals, barely breaking sweat in either of his first two matches. Jan Hajek was dispatched 6-2, 6-2 and Daniel Koellerer fared even worse, going down 6-2, 6-1.

Karlovic in contrast has not looked that sharp. He received a first round boost when his opponent retired at 4-5 in the first set and then his second round match against the lowly ranked qualifier Alexandre Sidorenko was desperately close, Karlovic taking it in two tiebreaks.

Surprisingly it is the first time these two have played. Karlovic’s massive serving will make this a more competitive encounter than either of Cilic’s matches so far but Cilic is in the form of his life right now and his groundstrokes are far too heavy and consistent for Karlovic to give him any real problems from the back of the court.

Cilic may require one or two tiebreaks but he should come through in straight sets.

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