PHOENIX — Brittney Griner swatted away just about everything within reach in the first quarter, setting the stage for a Phoenix rout.

Griner set a playoff record with eight blocked shots, five in the first quarter, and the Mercury soared past the Chicago Sky 83-62 on Sunday in Game 1 of the WNBA Finals.

“Her improvement this year has been incredible,” Sky coach Pokey Chatman said. “I don’t think people really appreciate it. They assume when you are 6-8, you are supposed to do everything. She has really evolved her game in the last year. She’s special.”

She showcased the remarkable mobility she has for someone who stands 6-foot-8.

“BG is a great help-side defender,” teammate Candice Dupree said. “If you get beat off the dribble, you kind of know that she’s back there.”

Griner, the WNBA defensive player of the year, also had 12 points and seven rebounds.

Dupree made her first 10 shots and scored 26 for the Mercury in their 19th consecutive home victory. Diana Taurasi added 19 points and 11 assists.

Phoenix shot a finals record 58.5 percent from the field, Chicago 31.9 percent.

Sylvia Fowles scored 19 points and grabbed 11 rebounds for Chicago but was just 8 of 20, usually against Griner in a matchup of the last two WNBA defensive players of the year. Elena Delle Donne only played 11 minutes because of a bad back. She finished with two points and didn’t play in the second half with the game already out of reach.

Delle Donne said she took herself out of the game because she thought she was hurting her team, and she hoped sitting the rest of the game out would make her better prepared for Game 2 of the best-of-5 series, set for Tuesday night in Phoenix.

“We’re definitely a resilient team,” Delle Donne said. “I still think we bounced back in the second half and put together a much better 20 minutes. I feel like we were able to settle in and get a little bit more comfortable and play with confidence, something we need to take in for the next game.”

Alley Quigley, who was the league’s sixth woman of the year, scored 13 points for the Sky. She missed 11 of her 15 shots.

Phoenix led from the opening basket, was up by 22 at the half and by as many as 30 in the third.

“I don’t think we ever quite recovered from that first quarter,” Chatman said.

“... We just got on our heels and never quite recovered from it.”

Griner’s five first-quarter blocks broke the playoff record for a half. She finished with six at halftime.

She expected the challenge in the paint.

“I knew they were going to come at me, definitely,” Griner said. “I would come at myself too. I wasn’t surprised at all.”

Meanwhile, Dupree couldn’t miss, going 9 for 9 in the first half, capped by a layup on a halfcourt pass from Taurasi just before the buzzer to put Phoenix up 42-20, the largest halftime lead in WNBA Finals history.

Griner dominated Fowles, blocking three of the Chicago center’s first four shots and holding her to 2 of 9 shooting in the first half.

Phoenix shot 64.5 percent in the first half (20 for 31) to the Sky’s 8 of 36 (22 percent).

Chicago, the No. 4 seed in the East, trailed just 17-12 after Fowles’ inside basket with 8:53 to go in the second quarter, then Phoenix outscored the Sky 25-8 the rest of the half.

DuPree scored six in a 10-0 run that made it 27-12 with 6:45 to go in the half, and Chicago never got closer than 12 again.

“Being that this was my first finals, I tried to not put too much pressure on myself,” Dupree said. “Just go out there and play the way I know how and take shots that I know I can make.”

Chicago rallied from a 17-point fourth-quarter deficit in the deciding first-round game against the East’s top seed Atlanta.

But there was no such comeback against the Mercury.

Phoenix scored the first eight of the second half to lead 50-20.