UNIONDALE, N.Y. -- Reilly Opelka had climbed out of trouble all week, though this time his big serve alone couldn't save him.
Technology did first.
Moments after an electronic review overturned what appeared to give his opponent a match point, Opelka pounded his 43rd ace to win his first ATP Tour title Sunday with a 6-1, 6-7 (7), 7-6 (7) victory over qualifier Brayden Schnur in the New York Open.
"I put myself in a good position throughout the whole match and third-set breaker could have went either way,'' Opelka said. "That challenge honestly is probably the difference.''
A night after overcoming six match points to beat top-seeded John Isner in the semifinals, Opelka needed six of his own to finish off Schnur in the matchup of first-time finalists.
The 6-foot-11 Opelka hit 43 aces for the second straight match, making him the first player to hit 40 or more in consecutive best-of-three-set matches since the tour began tracking aces in 1991.
But as powerful as he was with his racket, the pivotal point of the match came when he simply held it up in the air to signify a challenge.
Schnur had just hit what appeared to be an ace at 7-all in the tiebreaker that would have set up his first match point. But the review on the screen above the court showed it was just out.
Schnur, a rare player who doesn't bounce the ball before his serve, then put his second serve into the net for a double fault. Opelka closed things out immediately after with the last of his 156 aces in the tournament.
"I tightened up at the wrong time,'' Schnur said.
Schnur, who had never won a tour-level match before arriving in New York and making it into the tournament through qualifying, nearly pulled off a remarkable comeback after getting blown off the court in 18 minutes in the first set.
Opelka, a 21-year-old American who will climb more than 30 spots to a career-best No. 56 in the rankings, had to win second-set tiebreakers to win both his first two matches on the black courts of the Nassau Memorial Veterans Coliseum. He did so again in the semifinals against Isner, when they combined for 81 aces, the most ever in a three-set match.
Things appeared like they would be much easier Sunday. Schnur opted to let Opelka serve first and won the first two points, then won only one more on Opelka's serve in the set. Opelka had a 25-9 edge in points and 9-0 in aces in taking the set easily.
Even after a tougher second set, Opelka had two match points in the tiebreaker. But after only double-faulting once in the semifinals, he had a double fault on the second match point, and Schnur forced the deciding set.
Fighting the flu after playing in a lower-tier event last week in Dallas, the three-time All-American at North Carolina wasn't even sure he'd give it a shot in New York. He ended up the final alternate accepted into the tournament's qualifying draw, and played his way into the main draw after he was 0-5 previously in tour-level events.
He had upset seeded Americans Steve Johnson and Sam Querrey en route to the final but couldn't close out the week with a victory and fought tears in the award ceremony.
"Obviously coming from Dallas I wasn't even sure if I was going to show up here. I wasn't feeling good, I was tired and just ended up coming here, and obviously making an ATP final blows my mind,'' Schnur said. "It's been an unbelievable week and I've soared to new heights in the ranking and things are going to change, but obviously it just sucks to go down the way it happened."