Each of the Sparks' three previous games against Phoenix this season had been decided by a single point.
On Tuesday, it wasn't even close.
After falling into an early 20-point hole, the Sparks never came closer than six as the Mercury won, 98-89, at Staples Center.
"Same old story," Sparks Coach Jennifer Gillom said. "We always miss that one quarter."
Phoenix (7-11) came out shooting, making 60% of its shots in the first quarter to take a commanding 30-10 lead. Guard Diana Taurasi, the league's leading scorer, scored 11 in the quarter and finished with 30 points.
"If a player like her gets in a zone, they're hard to stop," Gillom said. "I think that's what she got in tonight. She was in a zone, and it was tough for us."
The Mercury scored 20 fastbreak points to the Sparks' nine — which, Gillom pointed out, was a key difference in the game.
"Our offense should not dictate our defense," Gillom said. "We have to come out and when we're not scoring, that's when our defense needs to be more aggressive. We come out in the second half and we start scoring and our defense is great."
The Sparks (4-13) began to recover in the second quarter and mounted a comeback in the third, outscoring Phoenix, 29-18, and out-rebounding the Mercury, 11-7. But they couldn't overcome the first-quarter deficit.
Forward Delisha Milton-Jones led the Sparks with 20 points, 12 in the second half. Forward Noelle Quinn and center Tina Thompson finished with 18 and 10 points, respectively — all in the second half. Kristi Toliver had 16 points and five rebounds in 27 minutes off the bench.
"I think that it's up to each of us as individuals to come out and be motivated, to have that sense of urgency not when we get down but from the beginning, so we won't have to dig ourselves [out of] a hole every game," Quinn said.
The Sparks remain in fifth place in the six-team WNBA Western Conference, now 11 1/2 games behind leader Seattle. However, Gillom said the team has not given up on a playoff bid.
"There's a ton of games to play," she said. "We are still in this thing."