PHOENIX — Heading out of the huddle with five seconds left and Game 3 of the WNBA Finals in the balance, everyone in the building knew what was coming.

This was A’ja Wilson’s moment to further grow her legend, an opportunity to drain a trademark game-winner that would be a highlight in the video montage for her future Hall of Fame induction.

Becky Hammon didn’t even need to use the whiteboard to tell her team what to do at that point.

“Get the ball to A’ja and get out of the way,” Hammon said Wednesday night. “That’s all the play was.”

The Mercury, who tied the game after trailing by 17 at the start of the fourth, expected that to happen, too. DeWanna Bonner and Alyssa Thomas were tasked with trying to cleanly stop Wilson or force her into the toughest shot possible.

Jackie Young started to move, which stalled Thomas for a moment.

When she refocused on Wilson, though, it was a millisecond too late. Wilson was already spinning, creating separation from Bonner. She rose up over Thomas and let the ball go.

“[When] she gets the eyes on the rim, it’s gonna be tough,” Hammon said after the Mercury’s 90-88 win. “I wouldn’t say it was some crazy play. She just made a crazy shot.”

Wilson’s only basket in the final 4:40 in regulation — a go-head bucket that left only 0.9 seconds left on the clock — felt like a death sentence for the Mercury, as the 3-0 lead in the seven-game series has proven to be fatal.

The Aces are a win away from their third title in four years.

Wilson’s dagger was a metaphor for what happened to Phoenix in this WNBA Finals series through the first three games. Bonner, who stood no chance of stopping Wilson, was a microcosm for her team.

Phoenix finally met its match.

The Mercury needed to take down two of the league’s juggernauts to get to this point. They beat the defending champion Liberty in three games. Then in the semifinals, it took only four games to slay the top-seeded Lynx, who were favored to win it all this month.

But the Aces, led by Wilson, may just be too powerful, too deep, too experienced and overall too good for the Mercury to conquer as Las Vegas put Phoenix’s season on life support and is eager to pull the plug Friday in Game 4.

The Mercury’s greatest problem heading into this series was how to deal with Wilson. Through 12 quarters, they still don’t have a solution.

Wilson poured in a remarkable 34 points and had 14 rebounds — making her the first player to have consecutive WNBA Finals games with at least 25 points and 10 rebounds.

It was Wilson’s ninth 30-point playoff game, the most in league history. Her 291 points in these playoffs — with at least one more game to go — is the most points in a single postseason..

The game shouldn’t have ended as close as it did. The Aces had the Mercury right where they wanted them, with Phoenix trailing by those 17 points heading to the fourth.

But two of the Mercury’s only three WNBA champions, Kahleah Copper and Bonner, willed Phoenix back into the game — even after losing Satou Sabally to an apparent head injury at the 4:26 mark of the fourth.

Copper scored 11 of her 17 points in the final quarter. Bonner had nine in the fourth and tied the game twice in the final 1:41 of regulation.

But the Aces didn’t crack and their four-time MVP starred in the biggest moment. She’s had many of those. But this one — a game winner in the WNBA Finals — hits differently.

“These are the moments that you dream of,” Wilson said. “These are just the times that you see on TV. Sometimes you’re watching, you’re like, ‘Oh my God to be in that building.’ And it’s truly powerful.”