The world number 10 advanced to the 23rd ATP final of his ‌career after striking 13 aces and 24 winners while committing 16 unforced errors, compared ‌with Nakashima's 27.

Fritz took control of a tight opening set when ‌he moved 4-3 ahead before earning the decisive break. The 28-year-old then served ‌out the set in 34 minutes.

Nakashima, seeking his first ATP ‌500 final, responded strongly in the second set. He broke Fritz to go 3-1 up, held to love for a 5-2 lead and closed out the set two ‌games later to force a decider.

Fritz regained control ⁠from the outset in the ‌third set, breaking in the second game before holding to love for a 3-0 ​advantage. He maintained the pressure to seal victory and book his place in the final, where he will face Spain's ​Rafael Jodar.

"Grabbing that break in the third set made the difference," Fritz said. "It was really a narrow margin the whole time. Not a ⁠lot of chances either way.

"First ​set I took my chance, in the second set he did. I played a really good break point in the third set, and I dug very deep to just keep holding."

Later on Saturday, Jodar fought back ‌from a set down to clinch a 6-7 (6), 6-4, 6-4 victory over Chile's Alejandro Tabilo.

"I knew I was playing well, having opportunities," Jodar said.

"Accepting all the moments that I didn't break in the first set and the beginning of the second set, accepting those moments helped me get the break in the second set.

"From then, I started playing with more rhythm with my serve, so mentally I was very good today."

The win was a reminder of Jodar's remarkable rise over the past ‌few months, with Tabilo having won the last meeting between the pair ​6-1, 6-2 in March at Indian Wells.

At the time, Jodar sat ‌outside the top 100, but an impressive run during the clay season, which included his first ATP title at the Grand Prix Hassan II in Morocco, has catapulted him up the rankings.

Courtesy of his performance in Washington, the 19-year-old will break into the top ⁠20 when the latest world ⁠rankings are released on Monday.