Gauff (left) and McNally won last year's US Open junior women's doubles title
American teenager Coco Gauff has won her first WTA title with victory in the Washington Open women's doubles.
The 15-year-old, whose stunning form at Wimbledon saw her reach the fourth round, won with compatriot Catherine McNally, 17.
The pair beat Hungary's Fanny Stollar and American Maria Sanchez 6-2 6-2 in a match that lasted 65 minutes.
"I think for me, and I think for both of us, [the title] means a lot," Gauff said.
"Obviously we want to do well in singles, but I think we just love competing in general, so whether it's singles or doubles, we want to win no matter what.
"We get as nervous in doubles as we do in singles because we just want to make the other one proud."
The tournament was Gauff's first main-draw appearance since Wimbledon, where she beat Venus Williams on her way to the last 16.
Her run at SW19 made her the youngest woman to reach the second week at the All England Club since Jennifer Capriati in 1991.
She was beaten by Kazakhstan's Zarina Diyas in straight sets in the first round of the Washington Open singles before going on to win in the doubles.
McNally reached the semi-finals of the singles before losing 7-6 (7-5) 6-2 to Italy's Camila Giorgi.