They have now won seven straight games when they lead a playoff series 3-2. After allowing four goals in three straight games, Vegas goaltender Carter Hart stepped up with 21 saves in Game 6.
Vegas will be facing the Anaheim Ducks in the second round, who eliminated the reigning Western Conference champion Edmonton Oilers in six games.
Anaheim has scored the most goals (26) of any team in the first round, while Vegas is tied with the Minnesota Wild with 23 for second place.
Recap & Highlights
After one Utah Mammoth power play and 15 minutes into the first period, it was the Golden Knights who would get on the board first.
Brett Howden scored his fourth of the series, and in his third straight game, to make it a 1-0 game with assists from Mitch Marner (5) and Mark Stone (3).
It marked Stone's 39th playoff, tying Jonathan Marchessault for the third-most all-time in franchise playoff history. He now sits behind current teammates Reilly Smith and Shea Theodore (51).
Should Howden score in the next game, he will tie Marchessault and Alex Tuch for the longest playoff goal streak (four games) in franchise history.
It also marked Howden's third goal on the road these playoffs. Only Marchessault (5) scored more on the road in a single playoff series for the Knights.
After Utah failed to score on their lone power play of the second period, the Knights doubled their lead after Mitch Marner finally found the net for the first time these playoffs.
Marner now joins Max Pacioretty, Paul Stastny, Stone, and Smith as the five players who recorded at least six points in their first six playoff games as players for the Knights.
But with 12:18 left to go in the game, the Mammoth would finally breathe life into their home arena.
Kailer Yamamoto scored his fourth career playoff goal, and his first of the series, to cut the lead in half to 2-1. Mikhail Sergachev earned his fifth assist of the playoffs, while MacKenzie Weegar earned his third.
It was their first shot on goal in an eight-and-a-half-minute stretch. They would eventually reach 20 shots on goal for the game, 59 seconds after the goal.
Just when things started to look like a rally for the Mammoth, the Knights made sure the fans sat back down in their seats only two minutes later.
Colton Sissons scored his second goal of the series to make it a 3-1 game with 10 minutes to go. Brayden McNabb (2) and Kaedan Korczak (1) picked up the assists.
Vegas' +37 goal differential in the third period during the regular season wasn't just the best of any team in the NHL - it was the best of any team in any period all season long.
The final dagger of the night would come just a little more than two minutes later, which officially put the game out of reach as Utah's elimination was inevitable.
Following a Logan Cooley penalty for high-sticking, Marner scored his second goal of the game to make it 4-1 with under eight minutes to go.
Theodore now moved into first on the Knights' all-time playoff assist list with his 52nd, jumping Smith (51). Meanwhile, Jack Eichel picked up his eighth assist of the playoffs, the second most among active players on teams still in the playoffs.
Cole Smith would pick up his second goal of the series with the unassisted empty netter to make it a 5-1 final.