Highlights of singles 2nd round matches at US Open

Stan Wawrinka of Switzerland hits a return during the men's singles second round match against Ugo Humbert of France at the 2018 US Open tennis Championships in New York, the United States, Aug. 29, 2018. Wawrinka won 3-1. (Xinhua/Liu Jie) (Xinhua/Liu Jie)