MELBOURNE, Australia (AP)—Marin Cilic has ended Juan Martin del Potro's chances of winning consecutive Grand Slam singles titles, beating the 21-year-old Argentine 5-7, 6-4, 7-5, 5-7, 6-3 in the fourth round of the Australian Open.
Del Potro lost to Roger Federer in the quarterfinals here last year, but avenged that by beating the 15-time Grand Slam winner in the U.S. Open final in September.
Cilic, whose best previous finish at Melbourne Park was a fourth-round loss to del Potro last year, clinched it on his first match point Sunday when del Potro's backhand went long.
The Croat was a quarterfinalist at last year's U.S. Open, where he lost to del Potro.