The Latest: Heat policy in effect again at US Open

              Sloane Stephens, of the United States, smiles after defeating Elise Mertens, of Belgium, during the fourth round of the U.S. Open tennis tournament Sunday, Sept. 2, 2018, in New York. (AP Photo/Adam Hunger)

NEW YORK (AP) — The Latest on the U.S. Open tennis tournament (all times local):

2:05 a.m.

Defending champion Rafael Nadal shockingly was shut out in the first set of his U.S. Open quarterfinal before coming back to beat No. 9 seed Dominic Thiem 0-6, 6-4, 7-5, 6-7 (4), 7-6 (5) in 4 hours, 49 minutes.

It was only the fourth time in 282 career Grand Slam matches that Nadal lost a set by a 6-0 score. It’s the first time he won the match after that kind of start.

This one was never easy: Nadal trailed by a break in the third set before taking it. He came within two points of victory late in the fourth set before being pushed to a fifth, where he was two points from a loss.

But Nadal held on and is into the semifinals at a third consecutive major tournament as he bids for a fourth U.S. Open title and 18th Grand Slam trophy overall.

He’ll face 2009 champion Juan Martin del Potro next.