The top-seeded former University of Georgia star has reached the finals in Atlanta in five of the past six years and is 20-3 in the event. He has 10 ATP Tour titles.
Even his dog, an English Cocker Spaniel named Magill (after Georgia's former sports information director and tennis coach, Dan Magill), was in Atlanta. His parents brought the dog to Atlanta from their home in Greensboro, North Carolina.
"I love this tournament. It's obvious," Isner said. "(Magill) is a good size to travel with, a little too big to fly. He's awesome, my best friend. He puts me at ease."
Isner beat an injured player.
The fifth-seeded Baghdatis began struggling physically early with a bothersome groin muscle/tendon that first flared up more than a month ago.
Shortly into a 59-minute match, the fifth-seeded Baghdatis knew he had a problem, and he felt it was worse because he had limited recovery time after his three-set win late Saturday night vs. Gilles Muller.
The 30-year-old Isner by that time was about six hours removed from a straight-set semifinal win over qualifier Denis Kudla.
"It's not a new injury . . . the muscles got really tight. I felt it immediately on my second serve and volley," said Baghdatis, who was playing in his 12th ATP final after falling in his previous seven semifinals. "I didn't want to show anything, but it was impossible to control it.
"It's always tough to have a match in (17) hours, especially when your opponent has (22). We are humans, you know, and you want to be able to play a final with the crowd loving it."
After scoring off Isner's second serve to start the match, Baghdatis was finished.
From there, he lost all 15 points on Isner's first serve in the first set, and scored just twice against Isner's final 38 service games. Plus, Isner registered whopping return win percentages of 39.1 and 45.2 percent in the two sets.
"I kept getting stronger and stronger," Isner said. "It was obvious that he was hurt on his second serve and volley. He's not a serve and volley guy . . . I just tried to stay aggressive."
Isner ripped 13 aces for 90 in four matches.
He jumped a spot in the world rankings, to No. 18, became the third American to win an ATP title this year (joining Jack Sock and Rajeev Ram), and the man American to win an ATP tournament three consecutive times since Andy Roddick prevailed at Queens Club in London from 2003-'05.
Baghdatis will move to No. 44 in the world rankings with a goal of finishing in the top 50 for the first time since 2012. He was ranked No. 8 in August 2008.
The Cypriot apologized to fans after the match, saying he plans to play at Washington.
"I'm sorry," he said when given a microphone to speak over the public address system. "My body was not able to keep up."