Vegas outshot St. Louis 21-4 in the second period.
"We only scored one, so you're never happy with all the looks," Golden Knights coach Peter DeBoer said. "I thought we generated some quality chances. We didn't have as much traffic as we had the last game. Sometimes you have to give the other goalie some credit, and he was obviously excellent tonight. ... We tried to get traffic there and a bunch of the looks, I thought we had some traffic in that area. But he fought through it and made some big saves."
Walman, a defenseman, scored at 13:31 of the third on a long rebound of Jordan Kyrou's shot to make it 3-0.
"I kind of blacked out a little bit, but it was a great play by our forwards to get the puck deep in the zone, and Kyrou made a good pass off the pad, I guess, and it came right to me and I was fortunate enough to put it in the net," Walman said. "The whole thing is kind of a blur looking back on it. I just … so many emotions, especially on this day. Great feeling."
Roy ended Binnington's shutout at 15:44 for the 3-1 final.
The Golden Knights were 0-for-4 on the power play.
"We competed and we did a good job keeping [shots] to the outside and clearing out rebounds," Binnington said. "The penalty kill was great. It's a good win for us."
NOTES: Binnington's previous NHL career high for saves was 46 in a 6-5 overtime loss against Vegas on Feb. 13, 2020. … The Golden Knights outscored the Blues 16-3 in the previous three games between the teams. … Vegas forward Chandler Stephenson returned after serving a three-game suspension for elbowing Los Angeles Kings defenseman Tobias Bjornfot. ... Blues forward Mike Hoffman, who has three goals in his past 20 games, was a healthy scratch for the second time in five games.