Defiant del Potro rallies for five-set win

NEW YORK» Juan Martin del Potro’s stay at the U.S. Open really should be over. It nearly was.

The 2009 champion at Flushing Meadows kept staving off defeat in the fourth round against No. 6seeded

EDominic Thiem on Monday. Del Potro was sick and looked sluggish, dropping the opening two sets with little resistance. Then he trailed by a big margin in the fourth set and faced two match points.

Still, del Potro was defiant, eventually working his way back on the strength of

Epowerful serves and thunderous forehands to edge Thiem 1-6, 2-6, 6-1, 7-6 (1), 6-4 over almost four hours to set a quarterfinal showdown against Roger Federer, who dispatched Germany’s Philipp Kohlschreiber 6-4, 6-2, 7-5.

“Thanks so much for all the support you gave,” del Potro told the boisterous Grandstand crowd that regaled the 24th-seeded Argentine with “Ole!” chants. “It helped me. I won’t forget this match.”

Thiem also aided del Potro by playing his worst tennis when he was closest to victory in the fourth set, which he led 5-2. Thiem served for the match at 5-3, but got broken. Leading 6-5, he drew within a point of winning at 15-40 on del Potro’s serve, but a pair of aces at 127 mph and 121 mph erased those two chances. The ensuing tiebreaker was dominated by del Potro, who closed it with a booming cross-court forehand winner on the run.

In the fifth set, del Potro won on his second match point, when Thiem doublefaulted. For the match, Thiem won more points, 141139.

It was by far the day’s most enthralling match, with spectators’ roars heard across the grounds to Arthur Ashe Stadium, where Federer played Kohlschreiber.

No. 1 Rafael Nadal got to the round of eight in New York for the first time since his 2013 title, overwhelming 64th-ranked Alexandr Dolgopolov 6-2, 6-4, 6-1.

Now Nadal plays a fifth consecutive unseeded foe in Andrey Rublev, 19, who took out No. 9 David Goffin 7-5, 7-6 (5), 6-3.

On the women’s side, Karolina Pliskova beat 91stranked American Jennifer Brady 6-1, 6-0. Pliskova will face No. 20 CoCo Vandeweghe, who beat Lucie Safarova 6-4, 7-6 (2).