Washington took a 2-1 lead at 1:27 of the second on Brian Pinho's shorthanded goal. Pinho stripped a Predator defender of the puck, then wound up and ripped a slap shot to the back of the net.
Late in the middle frame, Shane Gersich finished off a pretty tic-tac-toe play to extend the Caps' lead to 3-1, scoring from the left circle after taking a feed from Garrett Pilon, who just got it from Lucas Johansen.
The two-goal lead last only about three minutes; Nashville's Yakov Trenin scored to make it 3-2 with just 13.7 seconds left in the second.
Washington was the dominant team in the second period, particularly in the first half of that frame, but Trenin's goal was the first of three unanswered goals in less than six minutes. Olivier scored at 2:42, and Blackwell netted his second of the game on a Nashville power play at 5:16 to put the Preds up 5-4.
With the two teams playing four-on-four, Maximilian Kammerer tied it for the Caps at 13:33, going to the net and scoring on a timing play off a fine feed from Alexeyev to make it a 4-4 game.
"When you play four-on-four, you have a little more space to create some chances to score," said Alexeyev. "I tried once, tried to score, but it didn't happen. Then I make a pass, and we score."
But less than a minute later, Olivier scored a breakaway power-play goal that proved to be the game-winner.
Considering that they came together after just a single practice session on Friday and had mostly never played with one another before, the young Caps hopefuls played fairly well.
"That's the difficult thing because hockey is a team sport and it takes a little bit of chemistry to play with your [defense] partner or your linemates," said Carbery. "So it's tough. These guys are having to adjust on the fly and see if they can do everything they can to create a little bit of chemistry, to talk more, to try to read off one another. That's probably the most challenging thing, but you saw some good things from some line combinations - some guys finding each other - so that's good to see in the first game."