WASHINGTON -- Aerial Powers led six Washington players in double figures with 16 points and the Mystics beat the Seattle Storm 88-59 on Wednesday night.

The Mystics opened the third quarter on a 17-5 run for a 15-point lead as Seattle went without a field goal for four-plus minutes. The Storm pulled within 59-51 entering the fourth, but Washington scored 18 of the next 20 points.

Elena Delle Donne and Tianna Hawkins each scored 14 points for Washington (18-7), which won its fourth straight to sweep the season series. Kristi Toliver, averaging 13 points and six assists, missed her second straight game with a knee injury.

Natasha Howard led Seattle (14-12) with 24 points, eight rebounds, four assists and four steals. Mercedes Russell added 10 points.

Howard scored Seattle's opening eight points and ended the first quarter with 13 as the Storm led 23-16. Seattle was held to 12 points in the second quarter and trailed 38-35 at the break. Howard had 15 points, six rebounds, four assists and three steals at the half.