SEATTLE -- Breanna Stewart had 20 points and eight rebounds to help the Seattle Storm secure a playoff spot with a 78-60 victory over the Los Angeles Sparks on Sunday night.

The Storm led 49-27 at halftime behind double-digit scoring by Stewart, Sue Bird and Jewell Loyd. Eighth-ranked Seattle started the second half on a 7-2 run, capped by Stewart's 3-pointer, to extend its lead to 27 points and the Storm cruised to their first playoff berth since 2013.

Los Angeles, which already had a double-bye in the playoffs, rested starters Nneka Ogwumike and Kristi Toliver.

Crystal Langhorne added 15 points and 10 rebounds as all five starters scored in double figures for Seattle (15-17). Alysha Clark scored 15 points, Bird had 12 points and Loyd added 10 for the Storm, who won their fourth straight. Seattle was 18 of 18 from the free-throw line.

Candace Parker had 20 points and 10 rebounds, and Chelsea Gray, making her first career start, added 13 points for Los Angeles (24-8). The second-ranked Sparks lost their third game in a row for the first time this season.