Jerry Lai / USA TODAY Sports

The oppressive humidity in New York on Friday has made life difficult for the US Open men’s semifinalists. After Novak Djokovic and Gael Monfils took turns staggering around and keeling over in the heat during their strange afternoon match, a sweaty-palmed Stan Wawrinka felt the burn in the night session.

Wawrinka was up 4-1 in the third set against Kei Nishikori, and had a break point to go up 5-1. He got a decent look at a forehand pass, too, but his racket went flying out of his hand on the follow-through.

Nishikori went on to hold, then promptly broke to get back on serve.