It was the first power-play goal allowed this season by the Golden Knights, who were 4-for-5 on the penalty kill Monday and 7-for-8 through three games.
"The goal coming into this camp was to pick up where we left off in the bubble (on the penalty kill)," Vegas coach Peter DeBoer said. "At the end of the bubble, our penalty kill was a real weapon for us. We've got some chemistry in some of the people we're putting out there."
Pacioretty cut it 2-1 at 17:02 of the second period when he got his own rebound off the end boards and banked a shot from a sharp angle in off Kuemper's arm.
Vegas was outshot 27-15 through the first two periods but held a 13-5 advantage in the third.
Smith tied it 2-2 at 4:11 with a backhand in front after receiving a no-look, between-the-legs pass from William Karlsson.
"Hopefully [we] get off to a better start (going forward). This year is going to be unique," Smith said. "There's going to be strategy changes during games. We'll pick up pointers and make sure to adapt before next game."