Rafael Nadal is thwarted in the fourth round of the US Open, beaten by Frenchman Lucas Pouille in a memorable five-setter. - From ABC News Sport
Displaying poise beyond his years, the 22-year-old Pouille took charge early and led two sets to one, then rebounded after sagging in the fourth set to win 6-1, 2-6, 6-4, 3-6, 7-6 (8/6) in a four-hour struggle against the fourth seed.
Monfils, who has enjoyed a run of success this hard court season, maintained his impressive form with a 6-3, 6-2, 6-3 romp that kicked off a busy day for the French men's contingent at Flushing Meadows.
Wozniacki, a US Open finalist in 2009 and 2014 but unseeded this year after being sidelined for two months by an ankle injury, dominated from the start and wrapped up victory in a speedy 78 minutes on a sun-splashed Arthur Ashe Stadium court.
After rallying from a set and a break down in her opening match and then coming back from 5-1 down in the third to beat Japan's Naomi Osaka, Keys could not find a way round the former world number one, who took no chances closing out the match on her first match point.