It was a match neither player deserved to lose. Frenchman Lucas Pouille stunned No. 4 seed Rafael Nadal 6-1, 2-6, 6-4, 3-6, 7-6 (6) in a fourth-round thriller at the U.S. Open late yesterday afternoon. The final blow of the contest came when Pouille crushed his 59th winner of the day, an unplayable forehand down the line on the 22-year-old Frenchman’s fourth match point in a tiebreaker. Pouille collapsed on the court in exultation. Each player won 156 points in the 4-hour, 6-minute seesaw affair, which featured punishing ground games and dogged determination by both. Pouille, a rising star ranked No. 25 in the world and seeded 24th at Flushing Meadows, has come into his own this year, also reaching the quarterfinals at Brisbane and Wimbledon, the semifinals at Rome and the finals at Bucharest. “I think because mentally I’m stronger, physically I’m stronger, [that] gave me a lot of confidence before the match,” Pouille said. “I knew if I wanted to win that, it’s not going to be like three sets, 6-1, 6-2, 6-2. It would be long. So I was ready for it.” The young Frenchman will play fellow countryman Gael Monfils in the quarterfinals on Tuesday. Pouille started the match on fire, breaking Nadal in the second and sixth games of the opening set, and faced but one break point, that coming in the final game which he closed out with an ace. Nadal turned the tables in the second set with breaks in the second and eighth games to level the match. The Frenchman parlayed a break in the opening game of the third set to regain control and a two sets to one lead. In the fourth set, Nadal captured breaks in the sixth game and then again in the eighth, after Pouille had broken back in the seventh, to knot the match at 2-2. The Spaniard looked to be in the driver’s seat when he broke to open the final set and jumped out to a 3-1 lead. Undaunted, Pouille broke back in the eighth game and four games later a tiebreaker would determine the outcome. The Frenchman led 4-1 and 6-3 before Nadal leveled at 6-6. At that juncture, with Pouille serving, Nadal missed a short forehand put-away which would have given him a match point on his serve. Instead, Pouille followed with the decisive forehand winner for the mini-break to seal the win. “I learned that it’s never over until the last point,” Pouille said. “I was a break down in the fifth, I came back and led 6-3 in the tie-break and he came back. Yeah, it’s never done until the last point is over.” Although he only landed 46 percent of his first serves, Pouille had 11 aces and won 66 percent of the points on his first delivery and 58 percent on his second. The Frenchman saved six of 11 break points, Nadal nine of 14. “I fight until the end, until the last ball,” Nadal said. “It was a very close match. I congratulate my opponent, he played with better decisions than me the last couple of points.” Joining Monfils and Pouille in the quarterfinals is a third Frenchman, Jo-Wilfried Tsonga, who like his compatriots, also won his fourth-round match on Sunday. The trio become the first three Frenchmen to reach the final eight of a Grand Slam since 1947.