Tanisha Wright posted a game-best 16 points 55 at Key Arena.
Lauren Jackson scored 13 points, while Camille Little and Sue Bird each chimed in with 12 points as the Storm earned their second straight win.
Sophia Young led the way with 14 points -- including her franchise-best 3,000th point -- along with eight rebounds but the visitors dropped their fourth straight.
Jia Perkins tallied 11 points and six boards in the setback.
Seattle trailed by one heading into the fourth, but a 10-4 run at the outset gave it breathing room. Swin Cash started the period with a layup to put the Storm ahead, and Little ended the run with a deuce to make it 51-46. The home team never trailed thereafter.
Young hit the milestone on a shot in the second quarter. She became the 37th player in league history to score at least 3,000 points.