World number three Alexander Zverev beat teenager Alex De Minaur to defend his Washington Open title on Sunday.
Zverev beat the 19-year-old Australian 6-2 6-4 in the warm-up event for the US Open to claim a third ATP title this year after wins in Munich and Madrid.
"This match could be the final for the next 15 years so I hope you really enjoyed it," said the German, 21.
Russian Svetlana Kuznetsova beat Croatia's Donna Vekic 4-6 7-6 (9-7) 6-2 in the final of the women's event.
It was an 18th career tour title for the 33-year-old two-time Grand Slam champion, who had slipped to 128th in the world heading to Washington.