Dunn has three points (two goals, one assist) and is plus-4 in three games since being a healthy scratch against the Vegas Golden Knights on Jan. 26.
"It's always a surprise," Dunn said. "You're never really walking into the rink and thinking that's going to be happening to you, but obviously coaches make decisions and you obviously have to respect that and put your head down, work even harder. I guess it was just a reset for me. I didn't think I was playing that bad, but obviously I had a lot more to give. Obviously, that's behind me now and just trying to forget about it."
Sammy Blais, Colton Parayko and Jordan Kyrou each had two assists, and Jordan Binnington made 30 saves for St. Louis (7-2-1).
"I think every game is a little bit different," Blues coach Craig Berube said. "I didn't think we had a good start to this game, we were outshot 11-1 at one point, but we got involved and changed the momentum of the game, and that's what we're looking for. We're looking for responses.
"You're not always going to play your best hockey in certain parts of the game, but if you can change it and get a response from your team, that's a good thing. I think we're doing that right now."