The Canadiens were 1-for-2 on the power play. The Golden Knights were 0-for-2.
Pacioretty cut it to 3-1 at 4:09 of the third period on a wrist shot from the slot. It was the first goal by a top-six forward for Vegas in the series.
"Hard to explain. We didn't have great legs, didn't have great execution," Golden Knights coach Peter DeBoer said. "You have to give them credit. I thought they played a real good road game. And then obviously falling behind early against that team is tough. That's not a formula for success, we've shown."
Suzuki scored into an empty net with 1:06 remaining for the 4-1 final. It was the first three-point NHL playoff game for the forward, who was acquired by Montreal in the trade that sent Pacioretty to Vegas on Sept. 9, 2018.
It was the third straight game the Canadiens were coached by Luke Richardson since coach Dominique Ducharme tested positive for COVID-19 on Friday.
"We're definitely excited with what we're doing right now, but we don't want to get ahead of ourselves," Richardson said. "We finish off games the right way. We're going to go into the next game, and it's one game to win."
NOTES: Caufield has scored six points (three goals, three assists) in the past seven games. With eight points (three goals, five assists) in 14 games in the playoffs, he is the first Montreal rookie to score at least eight points in a single postseason since defenseman P.K. Subban in 2010 (one goal, seven assists). ... The Canadiens have not allowed a power-play goal in the past 12 games, the longest postseason streak since the NHL began tracking goals by strength in 1933-34. They are 28-for-28 on the penalty kill in that span. The 1936-37 Detroit Red Wings, 1939-40 New York Rangers and 1999-2000 New Jersey Devils each had a 10-game streak, tied for the second-longest. ... The Golden Knights are 0-for-13 on the power play in the series. ... Montreal improved to 7-2 on the road in the playoffs, tying its record for road wins in a single postseason, set in 1989 when it went 7-3. ... Kotkaniemi and Caufield became the first NHL teammates 20 years old or younger to each score a goal in a game in the third round of the playoffs since Sidney Crosby and Jordan Staal for the Pittsburgh Penguins in Game 2 of the 2008 Eastern Conference Final against the Philadelphia Flyers. ... Canadiens forward Paul Byron has two goals and two assists during a four-game point streak. He had an assist on Kotkaniemi's goal. ... Tyler Toffoli had two assists and leads the Canadiens with 14 points (five goals, nine assists) in the playoffs.