Liberty was at its best as it built a 17-point lead.
Sabrina Ionescu made 3-pointers from 29 and 30 feet.
Their developing offensive line regained some fluidity, some normalcy, even though Courtney VanderSloot was on the bench with back tightness.
But at their worst, the Liberty allowed the Mystics to chip away at a big lead and then take the lead into the fourth quarter.
Breanna Stewart was 4-of-13 from the field and 0-of-4 from 3-point range, and Ionescu had just 24 points after a 15-point opening frame.
That was still enough for a 90-79 victory Friday night at Barclays Center, but it was a disappointing showing for the Liberty, their sixth win of the season and second straight against the winless Mystics.
Stewart and Jonquel Jones both recorded double-doubles, and Kayla Thornton, who started in place of VanderSloot, scored 20 points, her most in a single game since August 2022.
The dagger also came from Thornton.
She was an under-the-radar acquisition by Liberty before last season, coming off the bench and not receiving the same attention as some of the other players on the superteam.
But with VanderSloot sidelined, Thornton started for the first time since 2022 and made a key 3-pointer with 2:06 left after Washington cut Liberty’s lead to four.
The Mystics couldn’t get any closer.
