The Miami Open is part of the ATP World Tour Masters 1000, the third highest tier of tournaments behind the Grand Slam tournaments and ATP Finals. Isner craves a first American victory since Andy Roddick for the tournament to bid a patriotic farewell to Key Biscayne's Crandon Park, which has been its home for 31 years.
Still, it was a successful tournament for the Americans, and even more successful for Isner, who first met Zverev, nicknamed Sascha, when the 20-year-old Zverev was 14 years old and hanging on the coattails of his older brother, Mischa.
"I don't talk about it too much, but [religion] is an important piece of my life", Isner said.
"You deserve to be a Masters 1000 champion", Zverev said to Isner during the postmatch ceremony. That one lasted two hours 38 minutes, took three tie-break sets, and Zverev won just two points more out of the 228 played saving three match-points along the way.
The second set was a tight affair, going into the ninth game with the match delicately poised at 4-4.
The 32-year-old spoke about what the victory over such a great rival meant.
Zverev blasted 10 aces and won 88 percent of his first serve points in his first career meeting with the 26-year-old Carreno Busta. He had, after all, withstood the determined David Ferrer and some of the best that the new generation of players could throw at him, the likes of Daniil Medvedev, Nick Kyrgios, and Borna Coric. "It's up to me now to keep pushing forward", he said. He was serving in the first set tiebreaker with a 4-3 lead but lost the next two points, the second on a double fault, to eventually lose the set.
"It's insane", Isner said.
Isner hugs Zverev after winning his first Miami Open title in three sets.
The second set looked to be following a similar pattern until Isner made a breakthrough late on.
"This atmosphere was electric, it was unbelievable, you can't replicate moments like this", he said.
Juan Martin del Potro of Argentina will face up to Milos Raonic of Canada in the Miami Open quarterfinals after both players beat respective rivals in the fourth round on Tuesday. What is more, his had been a tawdry start to 2018: six tour events played, one match won-until Miami.
When the match was over, Isner wrote: "He is risen" on the TV camera lens. "I played bad from the baseline".
She notched the biggest win of her career after seeing off the veteran star 6-2, 6-3 in straight sets. He's playing well so far this week, so it's going to be a hard match. After Sloane Stephens had taken the women's title on Saturday, this was the most complete weekend for American tennis since that same tournament in 2004, when Serena Williams had preceded Roddick into the winner's circle.