WATCH: Moment French youngster Lucas Pouille stunned Rafa Nadal at the US Open

Before this year, Lucas Pouille had only once got beyond the first round of a Grand Slam.

But now he finds himself one game from a US Open semi-final after causing one of the shocks of the tournament against number five seed Rafael Nadal. Nadal had looked comfortable throughout the first three rounds, seeing off Denis Istomin, Alessio Seppi and Andrey Kuznetsov without dropping a single set. But that changed against 22-year-old Frenchman Pouille, who took a dramatic fourth-round match 6-1 2-6 6-4 3-6 7-6 (8-6) at Flushing Meadows. https://twitter.com/FanSportsClips/status/772577920518754304 It was Pouille's first ever victory over a top-five player, and saw him achieve back-to-back quarter-final runs after making it to the last eight at Wimbledon in June. He has only reached the semi-final stage of an ATP tour event on two occasions, losing to Andy Murray in Rome in May this year and seeing off Federico Delbonis at the Romanian Open only to come up short against Fernando Verdasco in the final. But victory over Nadal is nothing short of sensational, and it sets up a tough-but-winnable meeting with compatriot Gaël Monfils in the quarter-finals. Murray has a chance to join Pouille and Monfils in the last eight when he faces off against Grigor Dimitrov on Monday night.