The trivia question posed to the fan was simple.

The big screen at the BB&T Atlanta Open just outside of Atlantic Station read, "Who is the highest-ranked American male in tennis?" Everyone seated at the court knew the answer was John Isner, who was resting in between sets on the bench. His opponent, Reilly Opelka, knew that, too.

But he didn't seem to care, and with good reason.

Opelka took Isner, the No. 14-ranked male player in the world and the No. 1 seed in the tournament, to his brink Wednesday night. And Opelka ultimately won, claiming the victory off a 7-5 tiebreaker in the last set. The final stat line was 7-6, 6-7, 7-6. It’s the first time Isner has lost in Atlanta prior to the semifinals. His all-time record in the tournament is 31-5.

“This is his tournament and it always will be,” Opelka said. “He’s a tough guy to beat in Atlanta. He was probably the better player in that match, so I was happy to be able to find a way to win.”

The match lasted about two-and-a-half hours and consisted of three tie-breaking sets. Clearly Opelka, 21, who entered the tournament unseeded, was not intimidated about playing a player 13 years older than him. In fact, Opelka seemed to be the more even-keeled and poised. Isner often showed visible frustration through his body language. He almost slammed his black and neon-pink racket at one point and returned to his bench with his head down, looking deflated.

He's performed well at this tournament before, which is essentially a homecoming for the former Georgia Bulldog --- the crowd certainly cheered louder for him. He has won it five times, and even reached the semifinals of Wimbledon a year ago. But Opelka boasts a stout record, too, as he's coming off a 2019 New York Open win in February.

“In a match like that, it’s literally a coin flip,” Isner said. “He serves well, I serve well and that’s what happens. I had some chances, but he erased some. Then it came down to a tiebreaker and he won one return point and I didn’t. That’s the case of the match, it’s as simple as that.”

The two towering men (Isner is 6 feet 10 inches tall, Opelka is 6-11) know each other well, which made for competitive games, leading to even closer sets. Before Wednesday,they played each other three times, and Opelka took two of them. Eight of their 10 sets have ended in tie-break.

That pattern continued in Atlanta. Isner could never create much separation from his opponent on the scoreboard . Every time he won a game, Opelka would win the next one. Opelka, though, dominated the first tiebreaker, winning 7-2. Isner barley won the second one, edging him 7-5. Isner had two more aces than Opelka (33-31), but Opelka earned more points than him (116-106).

“I was clutch on big moments of the match,” Opleka said. “John’s so consistent with his serve, so it’s hard to play three tiebreakers with him because there’s so much pressure, so much stress. Playing him almost three hours straight is tough, so it was a thrill to get through.

“At the end of the day, we both played really good tennis. John’s still top 15 in the world and I’m doing well myself.”