LAS VEGAS >> In any level of basketball, whether he’s played or coached, Bill Laimbeer has always thought guards decide playoff games.

That’s exactly what his guards did tonight.

Kelsey Plum scored 20 of her 25 points in the second half, and Riquana Williams scored a game-high 26 to lead the Las Vegas Aces in a 96-90 victory over the Phoenix Mercury in Game 1 of the WNBA semifinals.

Chelsey Grey pitched in with 17 points and 12 assists in the Aces’ first home playoff game in two years. Las Vegas reached the WNBA Finals last season while playing in a bubble in Bradenton, Florida.

“I think they were giving different reads on different people, and we were just taking what the defense gave us,” Grey said. “The guards have the ball in their hands a lot of the time, especially in transition. We dictate a lot of the game. That’s basketball in general, but it really tightens up when it comes to playoff basketball.”

Plum, the fourth-year guard who won an Olympic gold medal in 3-on-3 basketball, had 12 points in the third quarter off the bench as Las Vegas pushed its lead into double digits.

“We don’t really care necessarily about the numbers, about scoring on the bench,” Plum said. “We’re really just focused on how we can uplift our team and give us an extra burst going into second and third quarters.”

Phoenix, which won single-elimination games against the New York Liberty and defending champion Seattle Storm to reach the semis, led 30-21 after the first quarter.

“We never gave up,” Mercury coach Sandy Brondello said. “We kept competing. I don’t think we executed as well as we wanted to, but we had a lot of good moments where we played well, and other moments where we couldn’t score or we were just giving them what they wanted.”

Brittney Griner had 24 points, seven rebounds and six assists for Phoenix. Diana Taurasi, playing in her second game since returning to the lineup after sustaining a sprained ankle, scored 20 points on 6-of-17 shooting.

Taurasi walked to the podium with a walking boot on her left foot, but it was just a precaution.

“Once you’re out there, you’re out there,” Taurasi said. “Once you’re this deep into the season, no one’s feeling 100% and no one feels great.”

TIP-INS

Las Vegas had 12 assists total in its 84-83 win in Phoenix on Sept. 19. The Aces had 26 today. … The Aces had 22 second-chance points, while the Mercury had six.

GOING INSIDE

The Aces shot 8 of 18 in the first quarter, with seven of those attempts coming from 3-point range. In the second, the Aces shot 56% (14 of 25) to take a 52-49 lead at halftime. Las Vegas took its first lead with 4:05 left in the first half on a 3-pointer from Plum.

Las Vegas made it a priority to double Griner each time she got the ball in the post. That forced Phoenix to play a lot of inside-out in the second quarter. The Mercury were 1 of 6 from long distance in the second quarter.

“I think we were able to get stops and play transition,” Grey said. “When we’re able to get stops and play transition, we’re very difficult to guard. We were able to set up our half-court defense and it allowed us to play with our schemes and not play 3-point line to 3-point line.”

CAMBAGE’S CONDITIONING

Aces center Liz Cambage played her second game since returning from her bout with COVID-19. The former All-Star finished with seven points in more than nine minutes.

Part of that was due to foul trouble, finishing with four for the game and three in the first half. The other part was due to conditioning, which Laimbeer said took a huge hit in her play off the bench.

“She was off her feet for a bunch of days, uncertainty and the whole bit. People underestimate how much it took a toll on her,” Laimbeer said. “I don’t want her to fall down because she has nothing left.”

Williams scored 14 points in the opening 10 minutes to keep it close.

WILSON’S WILL TO WIN

Last year’s league MVP A’ja Wilson was kept in check for three quarters, but the Aces’ star came through at the right time.

With Las Vegas leading 85-81 and Phoenix making a run, Wilson went on a personal 6-0 run that pushed the lead back to 10 points with 3:08 remaining.

Wilson finished with 15 points and nine rebounds while going 7 of 12 from the field.

UP NEXT

Game 2 is in Las Vegas on Thursday.