SEATTLE  — Breanna Stewart had 21 points, 10 rebounds and eight assists, Sue Bird added season highs of 18 points and 10 assists, and the Seattle Storm beat the Washington Mystics 97-84 on Sunday to sweep their opening-round series.

No. 4 seed Seattle plays top-seeded Las Vegas in the second round. The best-of-five series begins next Sunday in Las Vegas.

Jewell Loyd was 5 of 10 from 3-point range and finished with 19 points for the Storm. Gabby Williams, who suffered a concussion in the third quarter and did not return, scored 14 points and Tina Charles added 10.

Ariel Atkins hit a 3-pointer 13 seconds into the third quarter to give the Mystics a 46-45 lead, but Stewart answered with a 3 on the other end and Seattle never again trailed. Stewart made a fade-away jumper to stretch the Storm’s lead to 17 points with 6 minutes to play.

Natasha Cloud made 5 of 8 from 3-point range and finished with 21 points for Washington. Atkins added 15 points and seven assists, Elena Delle Donne and Shatori Walker-Kimbrough scored 12 points apiece, and Alysha Clark 10.

The Storm made 35 of 63 (55.6%) from the field, shot 52.2% (12 of 23) from 3-point range. finished with 27 assists and committed a season-low eight turnovers.

WINGS 89, SUNS 79: Kayla Thornton scored 20 points and Teaira McCowan had 17 points and 11 rebounds to help Dallas win in Connecticut  to avoid elimination and win the franchise’s first playoff game since 2009.

The sixth-seeded Wings, who will host Wednesday’s Game 3, never trailed. They led by double digits for the final 26-plus minutes, despite a 22-2 fourth-quarter run that trimmed a 31-point Sun deficit to 84-73 with less than 2 minutes left.

“I think we have to learn how to capitalize,” McCowan said. “With us being a young team, you know, sometimes we get a little sloppy – as you could see at the end. But, I mean, once we tighten that up, it’ll be good for the next game.”

Allisha Gray had 15 points, eight assists and three steals for the Wings, and Marina Mabrey scored 14 points.

Jonquel Jones had 20 points and nine rebounds for third-seeded Connecticut, and Brionna Jones also scored 20. DiJonai Carrington added 13 points.

“I knew I had to go in and do what I do best, which is rebound, be a dominant force inside, and that’s what I did tonight for my teammates” said McCowan, who had seven points and five rebounds in Game 1.

“We have to put our talent to work. I mean, we know what we can do. We have great players on our team so if everyone plays their role, plays team offense and defense, we’ll be fine.

Dallas shot 48% (36 of 75) from the field, made 11 of 26 (42.3%) from 3-point range and finished with 28 assists.