Bria Hartley totaled 15 points, while Tianna Hawkins and Ivory Latta both contributed 11 off the bench as Washington topped Indiana, 79-63, on Friday.
Kia Vaughn picked up 10 points and seven boards for the Mystics, who won their first contest in 2014.
Maggie Lucas had 12 points and Briann January 10, with Erlana Larkins pulling down a game-best 12 boards in defeat, as the Fever remained winless in three tries this season.
The Mystics essentially wrapped this one up early, going up 26-12 after one quarter thanks to shooting 73 percent from the field, and never relinquishing the lead.
Washington's edge ballooned to 66-40 with 8:24 remaining on Ivory Latta's free throw, then the visitors cruised to the buzzer.