PHOENIX -- Brittney Griner scored 26 points and the Phoenix Mercury beat Seattle 70-60 on Sunday for their second victory over the Storm in three days.

Griner had 14 straight points for Phoenix in the third quarter, extending a 10-point lead to 58-42. Four free throws by Alex Harden made it a 20-point advantage.

Seattle, which outscored Phoenix 15-8 in the fourth quarter, rallied to within eight on Ramu Tokashiki's baseline jumper with 1:17 left, but Noelle Quinn found Griner underneath for an easy basket to seal the victory.

DeWanna Bonner added 11 points for the Mercury (8-5), who won at Seattle 94-79 on Friday.

Phoenix has won five straight games and has beaten the Storm eight consecutive times.

Jewell Loyd led the Storm (3-12) with 16 points. Angel Goodrich had eight assists in place of veteran point guard Sue Bird, who rested. Seattle has lost five straight and 10 of 11.

Griner and Bonner each scored nine points to pace Phoenix to a 42-27 halftime lead. Griner finished two points short of her career high. Her 15 third-quarter points were the most by a Mercury player this season.

"When she does the little things before the shot, she's difficult to guard," Mercury coach Sandy Brondello said of Griner's big third quarter.

Seattle made eight 3-pointers, twice as many Phoenix, but was outrebounded 44-37 and outscored in the paint 26-18. Phoenix also had a big edge at the free-throw line, making 16 of 19 to the Storm's 4 of 7.