French top seed Gael Monfils saved a match point and edged John Isner 6-4, 3-6 7-5 (8/6) in a rain-disrupted match early Sunday to reach the final of the $1.4 million ATP Washington Classic. Seventh-ranked Monfils will play for his fourth career title in Sunday's championship match at the hardcourt event against 54th-ranked Czech Radek Stepanek, who ousted American Donald Young 6-3, 6-3, in the other semi-final. Stepanek has dropped five of seven meetings with Monfils, including their most recent clash two weeks ago on Hamburg clay. "He's moving incredibly well," Stepanek said. "He's a great shotmaker." Big-serving American Isner and fleet-footed showman Monfils staged a classic despite a rain delay at the start and two interruptions that pushed the end to 1:15 in the morning, when Isner netted a forehand after a Monfils lob winner. Isner denied Monfils on two match points in the 10th game of the third set, smacking a forehand volley winner and a 130-mph ace on the way to holding. In the tie-breaker, neither player took a point off the other's serve until the decider. Isner blasted a 127-mph ace to reach his lone match point at 6-5, but Monfils answered with a 110-mph ace, setting up the drama-ending shots. Monfils reached his first US final, his first ATP final since last November at the Paris Masters event and only his second outdoor hardcourt final since 2006. His last title was last October at Montpellier. Monfils, 24, must win five matches in four days to claim a fourth career ATP crown due to rain that forced him to play twice Thursday. Isner, ranked 35th, had won 11 of his prior 12 matches but saw his career rivalry with the Frenchman leveled at 3-3. Isner, 26, won their first meeting in a 2007 Washington semi-final that went to three tie-breakers. Rain dogged Monfils and Isner, delaying their start, returning after they had played only seven points and striking again after Isner held to lead 5-2 in the second set. Monfils took the only break of the first set to lead 5-4 when Isner smacked a forehand wide and the Frenchman held serve with a 109-mph ace to win the set. But Monfils netted a forehand drop volley in the second game of the second set and Isner rode the break to claim the set, the only disruption coming during a pause after a 107-mph Isner serve hit a spectator in the face. Stepanek, the oldest player in the world's top 100 and oldest ATP finalist of the year at age 32, seeks his fifth career title in his first final since last year at Brisbane. Stepanek, whose most recent ATP title came in 2009 at San Jose, could crack the top 30 with what he said would be the biggest title of his career. "This tournament can give me a kick for the rest of the season," Stepanek said. "If I can make it to the US Open and be seeded, that would be great for me." Young, a 22-year-old left-hander set to jump from 128th into the top 90, was playing in the first ATP semi-final of his seven-year career. Stepanek broke Young in the fifth game of the first set and again in the last, the American sending a backhand volley beyond the baseline to surrender the break and the set. Stepanek won the first nine points of the second set, then fought off Young's only two break-point chances to hold for 3-0 and kept his serve to the finish, which came after 78 minutes on a service winner. "I was trying to attack his forehand so I could push him on his backhand on the court," Stepanek said. "I thought I worked it pretty well tactically."