Dallas led by double digits for most of the game until Ariel Atkins hit a 3-pointer with 1:03 left that got Washington within 81-74.
Tina Charles had 27 points and 10 rebounds to lead Washington.
LIBERTY 99, DREAM 78
COLLEGE PARK, Ga. (AP) — Sami Whitcomb and Betnijah Laney had 28 points each to help the Liberty beat the Dream.
Whitcomb made 7 of 12 from 3-point range and tied her career high with 22 points in the first half before setting a personal best after the break.
Laney had 19 points in the second half, Michaela Onyenwere finished with 18 points and Sabrina Ionescu had 10 points, six rebounds and eight assists, making her first start since missing a few games with an ankle injury.
The Liberty (8-8) never trailed and pulled away with nine straight points for a 58-46 lead in the third quarter.
Chennedy Carter had 23 points, Cheyenne Parker added 14 points and Courtney Williams scored 12 for Atlanta (5-9).