ROTTERDAM, Netherlands (AP) — Martin Klizan of Slovakia saved five match points against sixth-seeded Roberto Bautista Agut to set up a semifinal with French qualifier Nicolas Mahut at the World Tennis Tournament on Friday.

Klizan was on the brink of defeat but converted a break point with a superb forehand return down the line to level at 5-5 in the second set and prevailed 6-7 (5), 7-6 (6), 6-0 in a match that lasted nearly three hours.

Another stunning forehand winner sealed the second set tiebreak and Bautista Agut ran out of gas in the decider, winning just 16 points before bowing out.

"It was a real battle out there", said the 43rd-ranked Klizan after ending a four-match losing streak against the Spaniard. "Despite Roberto's match points, I kept fighting, because it isn't over until it's over. Of course you could see that Roberto played a lot of matches before."

Bautista Agut has already won two titles this season, in Auckland in January and Sofia last week.

Mahut dispatched eighth-seeded Viktor Troicki 6-2, 6-1 to reach the semifinals.

Mahut, the oldest player in the draw at 34, lost just three points on his first serve, saved the three break points he faced, and broke the 22nd-ranked Troicki four times.

Mahut, who is seeking a fourth career title, has now won five matches in a row in Rotterdam.

"Maybe I should file a request for more tournaments in Holland," he said. "It seemed as if Viktor was a bit tired after playing the final in Sofia last week. But things are going well for me here in Rotterdam, as I'm in the doubles semifinals as well."

The other quarterfinals at the indoor tournament pit fifth-seeded Gael Monfils against Alexander Zverev, and Philipp Kohlschreiber against second-seeded and former U.S. Open champion Marin Cilic.