Sue Bird poured in 21 points and Lauren Jackson 72, to record tying eighth straight playoff appearance.
Swin Cash had 13 points for Seattle, which shot 54.4 percent from the field and 42.9 percent from beyond the arc. The Storm halted their road losing streak at four games.
The Shock, who hold the league's worst record, were paced by Jennifer Lacy's 18 points. Amber Holt had 17 points and Tiffany Jackson chipped in 12 points and 10 boards.