Just 48 minutes have gone at Murrayfield as the bold call goes down to the sideline.
Wales, lucky to be only 17-8 down as Scotland butcher a try-scoring opportunity seconds before, are changing the half-backs.
Off goes Dan Biggar and Gareth Davies. In their place come Callum Sheedy and Kieran Hardy.
It feels significant. Very significant.
A statement, a message, a changing of the guard.
Call it what you want, but with Wales chasing a nine-point deficit, Pivac has placed his trust in two players with seven caps between them, not those with 144 Test appearances of experience to call upon. That's a bold call in anyone's book.
Now, Pivac has already taken his fair share of criticism as Wales coach.
Some of that is warranted. Some is just a touch unfair.
Last week's win against Ireland was denounced in some quarters as a poor, fortuitous Wales team stealing victory from a dominant Irish side thanks to a red card for Peter O'Mahony. For those following this narrative, the credit cannot go to Pivac.
Never mind the fact that while Ireland dominated territory and possession, they rarely looked like scoring - with 15 or 14 men - against a Wales defence that was comfortable to let a one-dimensional Irish team in front of them for large stretches.
Wales were clinical when they got near the Irish line and did what they had to.
The truth was the red card wasn't as much a factor as some would have you believe. More so, if that was Warren Gatland and Shaun Edwards up in the coaching box, the response to victory would be a little different.
But that's where Pivac's stock is right now. Welsh rugby lacks many things. Patience is one of them.
With all that in mind, you'd have forgiven him for not rolling the dice on 48 minutes.
But he did.
And it paid off.
There was of course some fortune, while this red card perhaps affected Scotland more than Ireland's last week as Scotland had to sacrifice a back.
But, in truth, the introduction of Hardy and Sheedy - as well as Willis Halaholo for his Test debut - had already began to turn the tide.
For 48 minutes, Wales struggled to get a foothold in the match.
Unlike last week, where Wales defended fairly passively and patiently against an Ireland side that went wide without ever really going forward, Scotland had pulled the Welsh defence around by getting wide and kicking in behind, pulling up the Welsh backfield and causing confusion.
When Wales did have the ball, they didn't seem to have too much up their sleeves.
The use of Justin Tipuric as a first or second receiver is an attacking nuance which Pivac has used well in the past two weeks, but Wales struggled early on to create much working off the half-backs.
An early set of phases was solid, eventually earning the penalty from which Leigh Halfpenny opened the scoring, but the fact of the matter was that Wales went through around 14 phases without ever really threatening to break the Scottish defence down.
Davies' delivery of service wasn't quite there, while Biggar seems to be taking everything static at the minute.
It's frustrating to watch. Wales kept the ball fairly efficiently, but the zip wasn't really there.
In the example above, Biggar takes it standing static and square - meaning that he has to generate the movement after receiving the ball.
Not only does this give the Scottish defence time to read what he's going to do, but it kills the timing of runs for options around him. Taulupe Faletau is left guessing on when an inside ball is coming as Biggar carries straight at the defence and the pass goes behind the No. 8.
The speed and accuracy of service was also awry.
Take this example with Tipuric slotting into the first-receiver. The openside flanker drops a little deeper to give himself the space to make decisions on the move - having thrown a miss-pass against Ireland last week after reading the defence biting in.
Something similar is on here, with Wales numbered up well in attack, but the pass from Davies to Tipuric isn't good enough and the Ospreys flanker has to check his stride to get it under control, allowing the Scottish defence to swallow him and force him inside.
Of course, Wales did cross for a first-half try, but that largely came from a bit of improvisation from Nick Tompkins helping Wales reach the edge.
Running off Biggar, the centre had threatened to have been swallowed up by the Scottish defence - with the movement from 9 to 10 not holding any Scottish defenders so far.
But, realising the importance of getting it wide, Tompkins just about managed to throw an unorthodox offload to Liam Williams, who put Louis Rees-Zammit over.
When it came to reaching the edge, it was the exception to the rule.
After a sloppy start to the first-half, Pivac acted. The impact was near-enough instant.
Having just came on, Hardy and Sheedy soon found themselves on the front-foot with Wales having an attacking lineout.
The initial Welsh driving maul was pulled down, giving them a penalty advantage, but what Wales did next was down to smart work from Sheedy - putting in motion a slick move that sliced the Scottish defence open.
From quick service from Hardy, Halaholo takes the ball at first-receiver - with Sheedy looping around him, having started positioned inside the centre.
Beyond Halaholo, Watkin runs a hard out-to-in line. Behind them all, Rees-Zammit is tracking across from his right wing.
Watkin's line off Halaholo holds the Scottish defence, while the Cardiff Blues' centre just throws in a little hitch kick as he receives the pass to sell the possibility of a trademark step.
With the Scottish 10-12 stopped from drifting by Watkin, Halaholo feeds Sheedy - who delays his pass enough just to force another Scottish defender to bite.
From there, it's a case of slipping Rees-Zammit through a gap and away to feed Williams to score.
Simple stuff executed well.
It didn't all go Wales' way after that, of course. Even after going down to 14 men shortly after, Scotland continued to frustrate Wales by pinning them back with repeated scrum resets that killed the clock.
But Wales still created enough opportunities from the limited possession they had to strike.
Remarkably, Wales have only spent a mere two minutes and 33 seconds in the opposition 22 in this tournament. That they have six tries to their name is a credit to their clinical efficiency.
The 9-10-12 axis that finished the game certainly helped grease the wheels a bit in that department, with Wales only really having what you could deem as four quality attacking possessions after the changing of the half-backs - scoring tries off three of them.
After Williams' try, the second saw Wyn Jones burrow his way over in the tight. The third resulted in a smart grubber from Sheedy pinning Scotland back, after some smart phase play that saw Wales stretch Scotland by working with their depth.
Whereas in the first-half, Wales seemed caught unsure how to play with the right depth and forward options - with Biggar often taking the ball static at first-receiver and at a depth that isn't quite flat enough to hold defences, but isn't deep enough to spread it.
Sheedy isn't afraid to give himself a yard or two extra to play with, while he often takes it from a pull-back pass from a forward - with Wales getting the ball into the wider channels late on and then working back to decent effect.
The speed of Hardy's service also helped, injecting some impetus into proceedings and helping Wales take on the Scottish defence before it had time to set.
On this occasion, the move doesn't result in anything as Hogg covers the kick behind from Sheedy, but minutes later, Wales would strike with the decisive score.
After some decent phases that saw Wales again reach the edges with similar work to above, the work of another replacement, Halaholo, and some individual magic from Rees-Zammit did the trick.
The quality of Rees-Zammit is undoubted, but the work by Halaholo pretty much explained why Pivac brought him into the squad.
"We haven’t been ruthless on the edges at times when we have created opportunities and Willis is very good in that department of the game, straightening up the attack and putting people in holes," said Pivac last week.
"He creates space."
It all starts with Sheedy taking the ball at first-receiver - with two forward options outside him and Halaholo positioned behind.
Sheedy gives himself some extra space, which in turn will allow the forward he feeds an extra split-second to make a decision in the face of the defence.
With the defences largely numbered up, Sheedy hits the first of those options - Adam Beard.
Beard has Leon Brown outside him and Halaholo behind. With Brown's straight line fixing the Scottish edge, Halaholo takes the pull-back pass from Beard and is immediately into space.
From here, Halaholo's ability to put people into space around the edges comes into effect.
Getting around Chris Harris, he sucks in Duhan van der Merwe, running straight at the winger to fix him before putting Rees-Zammit away.
The winger still has plenty to do, but his job is made significantly easier from the work done by Halaholo.
That Halaholo was out in that wider channel is down to how Sheedy marshalled the backline when he came on.
In the first-half, Wales looked a little limited with ball. Things were largely off nine, but there wasn't much variation.
That changed when Hardy and Sheedy came on.
The 9-10-12 axis of Hardy, Sheedy and Halaholo in that last quarter felt like the core of the back division that Pivac has wanted since taking over the reigns over a year ago.
As a result, he has some big calls to make ahead of England.
The good thing is we now know he's not afraid of making them.
