PHOENIX — Brittney Griner lounged in a baseline seat Wednesday as the clock ticked toward the start of Game 2 of the WNBA Finals, smiling, seemingly without a care in the world. Moments before she was joking with Portland Trail Blazers star Damian Lillard before she finished her pregame routine. She then spoke to reporters from the baseline, explaining how she’s able to stay cool in these pressure situations. Griner credited her dad, a Marine, for instilling that need to be tough under pressure.

When Griner stepped on the floor, she let her play speak for itself. Griner scored a game-high 29 points, including the first dunk in WNBA Finals history, to lead the Phoenix Mercury to a 91-86 overtime win, knotting the best-of-five series at a game apiece.

“We know who our bread and butter is,” Mercury guard Diana Taurasi said. "BG is just playing at a different level right now and there’s really nothing anyone can do. We knew coming into this game it was going to be a big focus. Got to get BG down low early and often. She sustained us for most of the game when offensively we didn’t really have a rhythm, and every time I looked up, she was making big basket after big basket when we weren’t playing well.

“That’s just what BG does, though. I think we take for granted sometimes how amazing she is.”

Griner put the Mercury on her back while her teammates struggled. She scored Phoenix’s first 10 points and then reasserted herself in the fourth quarter, finishing with nine rebounds. Taurasi overcame a slow start to finish with 20 points, including 14 in the fourth quarter and overtime.

Game 3 is Friday night.

The teams traded the lead six times in the fourth quarter, with neither the Sky nor the Mercury shrinking from the moment. Griner’s turnaround jumper with 1:22 remaining put Phoenix up 76-74. The lead grew to five, but Courtney Vandersloot forced overtime with a scoop layup with 4.4 seconds remaining to tie the game at 79.

Taurasi opened the extra period with a four-point play after getting knocked to the floor on a deep three-pointer from the right wing. Skylar Diggins-Smith came down with a dribble-drive layup to push the lead to 85-79, but the Sky answered with a 7-1 run to pull even.

Taurasi wasn’t done, however. She buried a three-pointer from the top of the key for a three-point lead before a layup from Diggins-Smith slammed the door shut. Diggins-Smith finished with 13 points, 12 assists and seven rebounds.

“That’s the GOAT right there,” Griner said of Taurasi. “We know what D can bring, doesn’t matter how she starts the game or whatever. You know when the time is going down, when it’s crunch time, we have all the faith in the world that D is going to make those shots and make big plays for us. She does it year in, year out.”

The Sky had four starters in double figures, led by Vandersloot’s 20 points and 14 assists, her third double-double of the playoffs. Allie Quigley had 19 points and six rebounds, Kahleah Copper chipped in 15 points and nine rebounds, and Candace Parker added 13 points and nine rebounds.

Sky Coach James Wade was particularly frustrated that his team shot just four free throws in an overtime game despite scoring 50 points in the paint.

“I just think they played more physical and I think they were allowed to,” Wade said. "We shot four free throws. Four free throws. Call it what you will. I’ve never seen that ratio in a league game before. You score that many points in the paint, that means you’re attacking the basket, and you shoot four free throws.

“I think when you attack the rim and you get fouled it should be called. That’s it. I don’t understand what “let them play” means. I’ve never heard that in a game. If they’re going to the free throw line, we should.”

The Mercury was determined to show that its lethargic Game 1 performance was a fluke after it had to play Game 5 of the semifinals less than 48 hours earlier. Phoenix didn’t make excuses, but the team flew back on the off day and never had a practice before it faced the Sky.

Players talked about starting fast now that their legs were back and just felt like their mojo had returned. That quick start, though, never happened. The Sky jumped out to a 17-10 lead with Griner the only Mercury player able to score a basket. Chicago led 26-20 at the end of the first quarter and looked like the more poised team despite having only three players with Finals experience and only one — Parker — with a ring.

“Obviously, we have a lot of different weapons,” Parker said. “So when they take one thing away, we’ve got to be confident and move it, and I think we did that early and we did that throughout the game in spurts. But we need a consistent 40 or 45 minutes of moving them. We can’t play their game where we come off; they’re too long and too active and too athletic.”

The Mercury, however, found a rhythm in the second quarter as Diggins-Smith aggressively attacked the basket and found teammates for buckets. She started an 8-0 run that tied things at 30, rebounding her own miss, sprinting out to the corner and burying a three-pointer. The teams went into the break tied at 40.

“It’s the Playoffs. It’s the Finals. We’re one down. This is our home court,” Mercury coach Sandy Brondello said. "We knew we needed to play with that sense of urgency. We look back at the film, that’s what I said, we’re a way better team than what we showed in Game 1. But we know it’s going to be hard because this team is really, really good.

“That’s what I talk about. Coach Monty [Williams] always sends me some quotes and it talked about excellence and you’ve got to do common things uncommonly well for long periods of time. That’s what happens if you want to be excellent at something. You’ve got to just grind it out.”