Sue Bird drained a pair of free throws with 1.6 63 victory over the Los Angeles Sparks.
Lauren Jackson and Tanisha Wright each had 14 points, while Bird had 12 for the Storm, who have defeated the Sparks in nine of their last 10 meetings.
Candace Parker paced Los Angeles with 19 points and 14 rebounds. Ticha Penicheiro added 15 points and 10 boards for the Sparks, who fell 1 1/2 games behind San Antonio for the fourth and final Western Conference playoff spot.
The Storm held a 51-43 lead through three quarters, but the Sparks reeled off 20 points over the final 10 minutes to climb within striking distance.
Following Bird's go-ahead foul shots, Tina Thompson had a look, but her 23- footer found iron at the buzzer.