Frances Tiafoe claimed his first grass court title on Sunday, saving a match point to defeat Germany's Jan-Lennard Struff in the Stuttgart final.
The American came through 4-6, 7-6 (7/1), 7-6 (10/8) and will move into the world top 10 for the first time on Monday, joining eighth-ranked compatriot Taylor Fritz among the elite.
The last time the United States boasted two men in the top 10 at the same time was in July 2011 courtesy of Mardy Fish and Andy Roddick.
Tiafoe withstood 28 aces from Struff who was bidding to become the first home champion since Michael Stich in 1991.
The 25-year-old Tiafoe saved the championship point at 6/7 in the third-set tie-break on his way to securing his second title of 2023 after Houston in April and third of his career.
He made a successful diving lunge on his third match point, just getting the ball over the net for victory after two hours, 12 minutes on court.
"I had to give it all on the match point," he said. "I hit an overhead but he got to it. I had to dive and got super-lucky. I was really happy to win."
Tiafoe will have little time for celebration with a flight to London to catch in time for next week's start at the Queen's Club Wimbledon tune-up tournament.
Struff, 33 and ranked 24th, kept a sellout crowd at the Weissenhof club enthralled as he delivered 28 aces but still missed out on the first title of his career.
He was a semi-finalist in 2019. The last German to reach a Stuttgart final was Philipp Kohlschreiber, who lost in 2016 to Dominic Thiem.
"It was an incredible match," said Tiafoe, who was playing his seventh career final.
"I didn't break him for two hours, 'Struffie' was serving well today.
He added: "It was just super-tough. On that match point, I don't know how I got the ball over the net, but I'll take it.
"It's good to walk away with the title."