Pacioretty scored 3:43 into overtime, completing Montreal's 3-2 come-from-behind win over the Boston Bruins on Saturday.
"I'm never going to live this one down but it's all a blur, all a daze," Pacioretty said. "I was just so excited about the goal and I don't think it was anything too big. I think he was just upset about the breakdown by their team, but it is what it is and it's a good feeling so I'll try not to let that ruin it."
Chara became incensed after he was shoved again when he approached the Canadiens' goal celebration. The 6-foot-9 defenseman tried to get at several Montreal players. He and 6-7 Canadiens defenseman Hal Gill were both given misconduct penalties.
"I don't really know what happened," Gill said. "I'm not going out there trying to start a fight, I'm trying to keep him from swinging at guys."
Bruins rookie Tyler Seguin was on the ice but didn't see Pacioretty shove Chara, who ignored reporters' requests to answer questions as he bolted from the dressing room to the team bus.
"After, he said that's what happened," Seguin said.
Montreal tied it with two goals late in the third. Scott Gomez scored a power-play goal at 17:38 to ruin Thomas's shutout bid and draw the Canadiens to 2-1.
Brian Gionta scored the tying goal with 47.7 seconds remaining in regulation, which brought on a huge ovation from those still on hand amid the sold-out Bell Centre crowd of 21,273.
"Well, we were down two goals. I don't think that's any reason to go home and hopefully they won't do it again," Gill said.
Carey Price stopped 27 shots for Montreal.
Thomas made 39 saves for the Bruins, who are tied with Montreal for the Northeast Division lead with 49 points.
"They found a way to win and we found a way to give it to them," Bruins coach Claude Julien said.
Bergeron scored his ninth goal 4:18 into the second. He added his second of the game -- his 10th -- at 12:27.
Montreal had an apparent goal by Mathieu Darche disallowed 7:57 into the third. Referee Kevin Pollock initially pointed to the net after Darche batted a rebound of James Wisniewski's point shot out of the air and into the net off Thomas' left glove.
Linesman Pierre Champoux immediately skated over to consult with Pollock, who then waved off the goal as he skated toward the official scorer with partner Stephane Auger. A video review upheld the referee's revised call.
"Those are the hustle plays of a guy going to the net and finding a way to get there and make a bounce go your way," Gill said. "We got that one called back but I think we saw that we can go at them and make good things happen."
Canadiens left wing Michael Cammalleri left the game in the second period and did not return. Montreal coach Jacques Martin said after the game that Cammalleri was sick.
- Bruins right wing Nathan Horton missed his first game of the season because of an undisclosed injury.
- The Canadiens have 1,833 wins, 748 losses, 382 ties and 37 non-regulation losses at home since joining the NHL as a charter franchise in 1917-18.
- Canadiens defenseman Roman Hamrlik returned after missing Thursday's shootout win over Pittsburgh with an undisclosed injury.