Gauff, a 19-year-old from Florida, did not drop a set all week in the hard-court tournament that is a tuneup for the US Open, which begins in New York on Aug. 28. This was her second trophy of the season, alongside one in Auckland, New Zealand, in January.
Gauff is ranked No. 7 and was seeded No. 3 in Washington, where she teamed with Caty McNally to win the doubles title in 2019.
The match briefly was interrupted in each set when a spectator was attended to in the stands on an afternoon with the temperature at about 90 degrees Fahrenheit (32 Celsius) and the humidity at 55%.
Gauff, the runner-up at the 2022 French Open, hit seven aces and improved to 4-1 in tour finals. Sakkari, a 28-year-old from Greece who is ranked No. 9 and was seeded No. 4, is now 1-7 in finals.
The men’s final was scheduled for later Sunday, with No. 9 seed Dan Evans of Britain facing No. 12 Tallon Griekspoor of the Netherlands. Griekspoor eliminated top-seeded Taylor Fritz in the semifinals, and Evans knocked off second-seeded Frances Tiafoe in the quarterfinals.
This was the first year of Washington’s tournament as a combined ATP-WTA 500 event. Despite that equal billing, the prize money is still not the same — and isn’t expected to be until 2027. Gauff earned $120,150, while the men’s champion was going to receive a check for $353,445.