WASHINGTON — Skylar Diggins-Smith scored 20 points and hit Theresa Plaisance for a clinching 3-pointer with 17.2 seconds left and the Dallas Wings got a critical road victory, 83-78 over the Washington Mystics on Saturday night.

Karima Christmas-Kelly added 12 points, including the go-ahead basket with 2:01 to play, to help the Wings (15-17) move a half-game ahead of Seattle, which is in the eighth playoff spot, and two games ahead of ninth-place Chicago.

The Wings were up three and got the ball after Ivory Latta stepped on the sideline with 36.6 seconds left. Diggins-Smith, who had seven assists, drove into the lane and kicked the ball back to Plaisance for the key bucket.

In her second game back for Washington after missing six games with a thumb injury, Elena Delle Donne had 29 points and 11 rebounds. Emma Meesseman added 22 points for the Mystics (17-14). They fell two games behind New York for a first-round bye in the playoffs.