The teams were initially followed in a hard and even match, where Colorado won the shooting statistics by 33-23.
It was a win or lose for the away team Colorado, who played together the most points during the regular season and thus won this year's Presidents Trophy.
And it started well for Captain Gabriel Landeskog and his men.
Only 23 seconds in, Devin Teows put 1-0 to Colorado.
Vegas, however, gave direct answers to speeches and acknowledged less than a minute later.
William Karlsson netted
Swedish star William Karlsson then made sure that Vegas took control of the match with a 2-1 goal at the end of the first period.
It was the 28-year-old's fourth playoff goal.
In a packed second period, the team took turns scoring every other goal.
Colorado's André Burakovsky reduced to 3-3 at the end, just to see how Vegas once again took the lead with only a few seconds left until the break.
In the third period, Vegas finally withdrew.
First with 5–3 and then the final result was nailed 6–3 in an empty box.
Vegas will face Montreal in the semifinal series, which has surprised in the playoffs and beaten both favorite tipped Toronto and Winnipeg.
Drop-offs for their first meeting will take place the night before Tuesday, Swedish time.
In the second semifinal, the Tampa Bay and New York Islanders, who play their first match on Sunday night, meet Swedish time.
Lehner patted again
The question is how much playing time will there be for Vegas' Swedish goalkeeper Robin Lehner in the continued playoffs?
Last night it was again Marc-Andre Fleury who excelled in the Vegas goal and Lehner has not played since the first game against Colorado, when Vegas lost 1-7.
Colorado won the first two games, before Vegas turned around and won the remaining four games.