June 7 (UPI) -- Veteran center Jonathan Marchessault completed a hat trick with a goal in each period to lead the Vegas Golden Knights to a win over the Colorado Avalanche, which tied the second-round Stanley Cup Playoff series at 2-2.
Fellow Golden Knights center William Karlsson register a trio of assists in the 5-1 Game 4 win over the top-seeded Avalanche Sunday at T-Mobile Arena in Paradise, Nevada.
The Avalanche won the first two games of the Western Conference series, but now must play at least six games to eliminate the second-seeded Golden Knights.
"We have to keep going," Marchessault told reporters. "We are on a mission right now. We just have to focus on Game 5 and bringing [the series] back to Vegas."
Avalanche left wing Brandon Saad drew first blood with a score 1:50 into the first period. Vegas netminder Marc-Andre Fleury did not allow another score.
Fellow Avalanche wingers Andre Burakovsky and J.T Compher put the puck in front of the net to spark the first goal. Saad recovered the puck through traffic and stabbed a shot inside the left post for an initial lead.
Karlsson assisted Marchessault's first goal about 5 minutes later. The Golden Knights harassed the Avalanche defense and stole the puck during that play. Karlsson then passed off to Marchessault, who buried a point-blank-range shot to sound the horn.
Golden Knights left wing Max Pacioretty scored the go-ahead goal 71 seconds into the second period. Mark Stone and Zach Whitecloud assisted that score, which came on a breakaway wrist shot.
Marchessault added to the Golden Knights lead midway through the bridge period. Defenseman Alex Pietrangelo and Karlsson exchanged the puck near the Avalanche blue line to set up that score. Pietrangelo then sent a pass to Marchessault, who smacked a one-timer past Avalanche goalie Philipp Grubauer for a 3-1 lead.
Karlsson and Reilly Smith assisted Marchessault's final score 6:01 into the final period. Smith fought for a loose puck on the left side of the Avalanche net during that play. He then sent a pass in front of the goal to Marchessault, who buried a backhander past Grubauer.
Golden Knights right wing Ryan Reaves and left wing William Carrier assisted Patrick Brown for the final score with 6:47 remaining.
Grubauer saved 30 of 35 shots in the loss. Fleury saved 17 of 18 shots.
"We all had confidence in this team," Fleury told reporters. "It's always tough when you go down 2-0, but we all knew we could come back and make it [a series]. ... We played a great 60 minutes. We just have to keep it coming."
Game 5 of the second-round series is at 9 p.m. EDT Tuesday at Ball Arena in Denver.