LAS VEGAS -- The biggest reason for the Phoenix Mercury's come-from-behind 87-84 win over the Las Vegas Aces to clinch a spot in the WNBA Finals on Friday night?
No, not Shey Peddy knocking down two of three free throws with 4.8 seconds to play to give the Mercury a two-point lead, though they helped.
Not even Brittney Griner's block of an A'ja Wilson driving shot that would have tied the game with 0.7 seconds remaining.
Ask Mercury coach Sandy Brondello, and the answer is obvious.
"In the fourth quarter, we have Diana Taurasi and they don't," she said, borrowing a decades-old yarn by Taurasi's college coach at Connecticut. "I'm stealing that off Geno [Auriemma], but that's what it comes down to.
"Diana making shots, that's what changed it. That gave us hope. You know, we're down by eight [points] at the start of the fourth quarter and Diana gave us hope."
As a result, the Mercury stole Game 5 in front of 9,680 at Michelob Ultra Arena -- an Aces record -- and will now have homecourt advantage against the Chicago Sky.
Taurasi had a relatively quiet start, missing her first five 3-point attempts Friday night, appearing to simply pace herself for three quarters. But then the WNBA's all-time leading scorer got hot. And not just because Aces guard Jackie Young got in her face at the end of the third quarter. Taurasi scored 14 of her 24 points in the fourth quarter, tied for the third-most in a winner-take-all playoff game since the WNBA moved to four quarters in 2006.
Included in that run was Taurasi hitting three of four from beyond the 3-point arc.
She is now 16-2 in winner-take-all games in her career, the best record in such games in WNBA history, according to the Elias Sports Bureau.
"You just can't care too much," Taurasi told ESPN after the game. "I cared a lot for about a year. You know, working out, I'm 39, able to play. In these moments, you just can't care anymore, you know what I mean? You just can't care that much."
This will be her first trip to the WNBA Finals since 2014, when the Mercury swept the Sky, 3-0.
"It's hard," she said. "It's been now, what, seven, eight seasons? And when you get there, you think you're just always going to get there. And that's not the case. I know the magnitude of this, and these guys have been great all year. This team has just been resilient all year. We've had injuries, this and that, and we've always been able to just stay together and like each other. Which is a big deal."
The Mercury actually led by 10 early, 20-10, and still held a 46-44 halftime lead.
But the Aces, who had a 24-0 third-quarter run in Game 4, went on a 14-0 run in the third quarter Friday night to take a 10-point lead of their own. They still led 64-54 late in the third.
Enter Taurasi, who keyed a 10-0 Mercury run with a pair of 3-pointers early in the fourth. Neither team led by more than four points the rest of the way.
Aces coach Bill Laimbeer credited the mental toughness of Taurasi and Griner for getting the Mercury over the top.
"They willed that unto their team," Laimbeer said. "They hung in there, they made the big plays. We need to acquire that trait. Whether it is we grow up or whether we acquire something, but it's something that this team has consistently lacked throughout the course of the year -- a leadership of steeliness. Someone that sits there and says, 'No, this is how we do it. This is what's going to happen.' And, they have it; we don't.
"Unfortunately, down the stretch we needed mental toughness. It didn't happen. We lost. And that's the way it goes."
You want mental toughness? Taurasi, who started the series with an ankle injury that severely limited her, is also on another clock. Her wife, Penny Taylor, was due to give birth to the couple's second child on Oct. 6.
"Hold it in, babe," Taurasi said, looking into the camera, "I'm coming."