Alex Pietrangelo delivered a goal and an assist Thursday as the Vegas Golden Knights beat the Colorado Avalanche 6-3 to reach the NHL playoff semi-finals. The Golden Knights, who won the final four games of the series, will play the Montreal Canadiens in the semi-finals. The reigning champion Tampa Bay Lightning will take on the New York Islanders in the other semi-final series for a place in the Stanley Cup final. Vegas' Marc-Andre Fleury made 30 saves for his 89th playoff win, moving him past Billy Smith and Ed Belfour for fourth place in NHL history. Two days after battling back from a 2-0 deficit to win in overtime, the Golden Knights clinched the series in front of ecstatic home fans. Devon Toews scored 23 seconds into the game to give the Avalanche a 1-0 lead. Nick Holden scored 52 seconds later to knot the score at 1-1, his wrist shot from the left point beating goalie Philipp Grubauer who was caught looking the wrong way for the puck. William Karlsson put Vegas up 2-1 at 15:06 of the first on a one-timer off a pass from Alec Martinez. Mikko Rantanen made it 2-2 at 3:47 of the second period with a power-play goal. Vegas took a 3-2 lead at 14:27 of the second when Keegan Kolesar deflected Pietrangelo's shot from the point. But the Avalanche were level again after Andre Burakovsky scored his first goal of the post-season at 16:52. With 18 seconds left in the second period, Pietrangelo gave the Golden Knights a 4-3 lead. Colorado failed to clear the zone, and Alex Tuch's spinning shot caromed off the boards to Pietrangelo, who beat Grubauer over his glove. William Carrier made it 5-3 at 11:46 of the third and Max Pacioretty added an empty net goal to cap the scoring. bb/ch