Frustrated by Monfils’ unpredictable style, flummoxed by the swirling wind, and missing shots he normally makes, Federer twice was a single point from losing while down 5-4 in the fourth set.
Colorful Gael Monfils is back in the US Open quarterfinals.
Gael Monfils beat Grigor Dmitrov 7-5, 7-6 (6), 7-5 on Tuesday to reach the quarterfinals of the U.S. Open for the first time since 2010.
13th-seeded John Isner lost to 22nd-seeded Philipp Kohlschreiber in the US Open’s third round for the second consecutive year.
Vera Zvonareva let her opponent self destruct, taking advantage of 60 unforced errors to win her U.S. Open quarterfinal 6-3, 7-5 over Kaia Kanepi on Wednesday.