Gunnarsson scored the go-ahead goal with 7:44 left in the third period, lifting St. Louis to a 3-2 win over the Ottawa Senators on Saturday night.
It was his first in 29 career games against Ottawa, and second overall goal in as many games since missing three games due because of an illness.
''A good shift all over there,'' Gunnarsson said. ''The forwards were fighting in front of the goal and they just kind of got jammed up in front of the net and I kind of got lucky on the shot.''
Gunnarsson has scored in his last five games, including the three previous before getting sick, a career high.
''He's a huge part of our team, not just offensively, but he's just so sound all over the ice,'' Blues defenseman Colton Parayko said. ''If you watch him, he's a huge part of the way we play and just a huge part of our success as a team.''
''It is what it is and our players have no control over it,'' Senators coach Guy Boucher said. ''Our goalie did everything he could and that's a clear, clear, clear, clear save.''
''I think the play was covered in my opinion, but the referee was on the other side of the ice and didn't see it, so there's nothing you can do about it so you have to move on,'' Anderson said. ''I think the indication was that most everyone on the ice stopped playing.''
Paul gave the Senators a 1-0 lead at the 4:34 mark of the first period with his first goal this season and first since Dec. 29, 2017.
Tarasenko tied it for the Blues at 7:50 of the first, beating Anderson glove-side off of a faceoff for his fourth goal in five games.
Dunn gave the Blues a 2-1 lead with 2:32 left in the second with a slap shot from the left point.
Paajarvi tied it one minute into the third after Zack Smith's pass went off of his skate and into the net for his first goal in nine games against his former team.
Blues forward Ryan O'Reilly, who had two assists including one on Gunnarsson's game-winner, liked his team's response after giving up the lead.
''Obviously it was disappointing, but I think we're starting to be more consistent and not deviate and selling the farm,'' O'Reilly said. ''Everyone's kind of not thinking about it. It's just kind of respond, `OK. what's next here? Let's get our feet going. Let's win some battles again.'''
FACES IN THE CROWD
St. Louis Cardinals players Dexter Fowler, Paul DeJong and Drew Robinson were at the game. The trio was in town for the Cardinals Winter Warm-Up fan event.
NOTES: Senators LW Brady Tkachuk played his first NHL game in his hometown. His father, Keith Tkachuk, had three different stints with the Blues from 2000-2010. ... Blues LW Alexander Steen (left shoulder) returned after missing six games. ... Senators RW Mark Stone is one away from 300 career points. ... Blues LW David Perron's career-high 13-game points streak was snapped after being scratched due to an upper-body injury suffered Thursday night. ... Senators D Mark Borowiecki was scratched after leaving Friday night's game in the second period with a lower-body injury and is day to day.
Ottawa: hosts Arizona on Tuesday.
St. Louis: at Los Angeles on Monday.
More AP NHL: www.apnews.com/NHL and www.twitter.com/AP-Sports
Copyright 2019 by AP. Any commercial use or distribution without the express written consent of AP is strictly prohibited.