Kristi Toliver scored 23 points to lead all five starters in double-digit scoring and the Sparks defeated the Storm 83-59 on Saturday.
Candace Parker scored 17 points, DeLisha Milton-Jones 15, Nneka Ogwumike 13 and Alana Beard 10. Toliver, coming off a career-high tying 29-point game, went 9 for 14 from the field to lead a collective effort by the starters.
Los Angeles did not get any points from its bench until Jantel Lavender scored with fewer than three minutes remaining.
"People have some good nights, some off nights, but if we can stay consistent and we have contributors like that and if we can maintain that tempo throughout the game. ... I think we have the advantage every time," Ogwumike said.
The Sparks (12-6) improved to 4-0 this season against the Storm, who finished the game with seven healthy players after Tina Thompson left with a leg injury in the fourth quarter.
Thompson had her left ankle bent awkwardly when Ogwumike fell on it with 7:12 remaining. Thompson was helped off the court and did not put weight on her left leg.
Seattle coach Brian Agler did not have an immediate update on her status.
Seattle was already without Sue Bird, its leading scorer and a member of the U.S. Olympic women's team, because of a hip flexor, and starting center and top rebounder Ann Wauters, who missed a second straight game with a strained calf. Agler said Wauters is doubtful for Sunday.
Agler said Bird is day-to-day. Bird didn't rule out playing Sunday.
"If I wake up tomorrow and feel good, I expect to play," Bird said.
Camille Little scored 12 points to lead the Storm (7-9), who had won six of seven and were coming off a win against Connecticut on Sunday.
But without Bird outside and Wauters inside for Seattle, the Sparks took full advantage and built off a win Thursday against defending champion Minnesota.
Sparks coach Carol Ross said she "couldn't be more pleased" with how her team continued to defend their court.
The Sparks improved to 8-1 at home.
"In the third quarter they were trying to scratch back, and coach was emphasizing in the huddle that they may not have Sue, but it's still Seattle," Ogwumike said. "It's still a good team."
Shekinna Stricklen scored 11 points in her first career start and Ewelina Kobryn also had 11 for the Storm, which also finished playing nine of 12 games on the road.
"Just like I told the team, I said 'No one's feeling sorry for us,'" Agler said. "Every team has had situations like this before. I thought we did a lot of good things today. We just didn't have enough weapons. I thought we could have played a little bit tougher defensively at times, especially in the first quarter and the third quarter. But I don't fault our effort. We competed."
Ogwumike pushed the lead to 21 points in the third quarter when she completed a three-point play after Toliver delivered her a pass inside. The Storm then went on a 6-0 run on baskets by Little and Stricklen before the Sparks closed out the third on a 3-pointer by Milton-Jones and a layup by Beard.
Beard opened the fourth with a 3-pointer to make it 66-43 and the Sparks led by double digits the rest of the way. Toliver made back-to-back jumpers to push it to 76-47.
"It's disappointing that we let it get out of hand," Katie Smith said. "We had it at a manageable point where we can maybe have a chance to get the W. But they played well, made some shots and got a nice cushion."
The Sparks took a 41-33 lead into halftime despite committing 11 fouls that resulted in 14 free attempts by Seattle. Parker scored in the paint and banked in a right-handed shot while Milton-Jones made a 3-pointer to maintain at least a six-point lead in the final minutes of the half.
Parker and Toliver accounted for 18 of the Sparks' 28 first quarter points. Parker swished a 3-pointer and rattled in another for a 27-17 lead before Milton-Jones made a technical foul free throw.