Bouillon scored at 1:26 of overtime to cap a wild third period comeback for the Canadiens, who erased a three-goal deficit with fewer than four minutes to play in regulation to defeat the Ottawa Senators 5-4 at Bell Centre on Saturday.
"It's maybe the most important goal of my career," said Bouillon, 38, who scored 30 goals in 763 career games prior to Saturday. "It's nice to have it in a game like that."
Lars Eller and Brian Gionta scored at 16:38 and 17:56 of the third period before David Desharnais scored on a power play with 0.3 seconds remaining in regulation to tie the game 4-4, with Canadiens defenseman P.K. Subban assisting on all three goals.
Bouillon scored in overtime when the puck popped out of a goalmouth scramble right onto his stick with a wide open net to shoot at, scoring for the first time in 62 games to allow the Canadiens to snap a three-game losing streak in the most dramatic fashion imaginable.
It was Canadiens goalie Carey Price's first game in three weeks after he missed eight games with a lower-body injury he aggravated playing for Canada at the 2014 Sochi Olympics. He finished with 30 saves, including several on breakaways and high quality scoring chances in the third period while his teammates pushed to tie the game.
He described the game rather perfectly afterwards.
"That was a gong show, I guess, to sum it up out there," Price said. "At the end of the day, that was a really big two points for our team. We needed that desperately."
With the Senators ahead 4-1 late in the third period, Eller snapped a 24-game drought with his 11th goal of the season at 16:38, converting a rebound of a Gionta shot.
Gionta then scored his 14th of the season at 17:56, tipping a Subban shot past Senators goalie Robin Lehner for the Canadiens captain's 14th of the season.
Kyle Turris was called for hooking with 1:48 to play and Canadiens coach Michel Therrien pulled Price for an extra attacker, giving Montreal a 6-on-4 advantage.
The puck came to Subban with fewer than three seconds remaining and, instead of shooting, he found Desharnais open to the right of Lehner and his shot beat the final buzzer to send the game into overtime.
"Give [Desharnais] credit there," Subban said. "As much as I have to find him, he's got to bury that."
Daniel Briere also scored for the Canadiens (36-25-7), who earned their second win in six games, but Therrien hopes the way they won can propel his team in the final push toward the Stanley Cup Playoffs.
"It shows the character of our team, they never gave up," Therrien said. "That's the No 1 thing for me, we found a way to win.
"What I'm hoping for is that can change a season, those big games like that."
But the Senators were far from pleased after the game, believing Lehner had frozen the puck before Bouillon scored the winning goal and also questioning some of the penalty calls that went against them.
"It's tough. We're fighting for our lives right now and it's hard not to get emotional," said MacArthur, who returned to the Ottawa lineup after missing two games with a hand injury. "We put ourselves in a bad spot and gave them a little life. But at the same time, it's tough enough playing a hockey team and not everyone else in the building. That's tough for us."
MacLean was also puzzled by some of the decisions made by referees Eric Furlatt and Dean Morton, but ultimately blamed the loss on his team's inability to hold a lead and stop the bleeding once Montreal made it 4-2.
"Right now it's frustrating," he said. "The last three-and-a-half minutes, the game's there to be won. But it's a perfect example that you've got to play longer and harder than the opposition if you hope to win the game. There's going to be circumstances in the game where you have to control your emotion and focus on the task at hand, and we didn't do a good enough job of that."
Spezza has three goals and seven assists in his past six games and Hemsky has a goal and six assists in four games since he was acquired from the Edmonton Oilers at the NHL Trade Deadline.
Price was welcomed with a huge roar from the fans when he was announced in the starting lineup for his first action since the gold medal game at the Olympics on Feb. 23.
However, his welcome by the Senators was not nearly as warm.
It took the Senators more than three minutes to test Price with a shot, but they made it count with Spezza taking an Erik Karlsson pass in the slot and firing a slap shot to the top corner past Price's glove hand at 3:08 to tie the game 1-1.
It was the first goal Price allowed in 167:27 of game action after stopping every shot he faced over the final 164:19 of the Olympics.
Karlsson's second assist of the night was the play of the game, and might be a candidate for the assist of the season.
With the Canadiens on a line change late in the second period, Karlsson curled back into his zone to retrieve the puck near his own goal line. When he looked up he saw Zack Smith breaking for the Canadiens zone and launched a saucer pass that traveled approximately 110 feet before landing perfectly on Smith's stick, allowing him to break in on Price and score his 11th of the season at 17:10 of the second period.
Hemsky scored at 1:54 of the third period when he was left alone in the slot to finish a Spezza feed. MacArthur made it 4-1 at 5:08 on a similar play, slapping home a Turris pass from about five feet in front of Price for his 20th goal of the season, one short of his career high.
Briere scored at 38 seconds of the first on Montreal's third shot of the game, a low wrister that beat Lehner to the stick side for his 12th goal of the season. After Spezza's goal at 3:08 made it 1-1, Briere was denied his 13th after the five-minute mark of the first when Alex Galchenyuk set him up with an open net on a power play, but Lehner slid across to make an outstanding pad save.
Ottawa outshot Montreal 16-9 and appeared to have taken a 2-1 lead at 14:50 when Colin Greening went in on goal and was tripped by Eller, crashing into Price before the puck dribbled into the net afterwards. The goal was initially awarded on the ice, but the four officials huddled up and decided that the goal wasn't good due to incidental contact with the goaltender, which is not a reviewable play.