The Oilers improve to 4-0 in the second game of back-to-backs after being handed a 5-2 defeat the night prior by the Pittsburgh Penguins, earning back a share of first place in the Pacific Division with their 20th victory of the campaign.
"It was a gutsy win," Sheahan, whose third goal of the season went down as the game-winner, said post-game. "Obviously we weren't satisfied last night with our effort, just making mistakes in certain areas of the ice not being totally detail-oriented, but tonight was good."
On another night where the Dynamic Duo of Connor McDavid and Leon Draisaitl made a meaningful impact, each recording a goal and assist after being reunited on the top line with Zack Kassian to reach the 60-point mark for the season, the Oilers received contributions throughout the lineup.
"The teams that do well are the teams that have depth," Sheahan added. "You see that in playoffs and down the line -- a lot of guys stepping up. Obviously we rely so much on our big guys, and they do a great job. They lead our team, but some nights they need some help."
"Everyone chipped in and we played a strong game."
The Oilers electric one-two punch atop the NHL's scoring race worked their regular 2-on-1 routine just 1:30 into the contest, with Draisaitl accepting McDavid's feed and putting home his 22nd goal of the season on the game's first shot.
McDavid's 40th helper pushed the Oilers captain to 60 points in his 39th appearance of the season.
The shared quest between the Oilers players and coaching staff to find more even-strength production had two hard-earned rewards through 20 minutes when Josh Archibald deflected this second marker of the campaign past Carey Price on last of a flurry of chances around the Canadiens net for the 2-0 lead.
Even after former Oilers defenceman Jeff Petry cut into the host's lead shorthanded with 5:41 to go in the opening frame and provided the point shot that was tipped in by Phillip Danault on the man advantage to tie the score, the Oilers power play made amends.
On its next opportunity before the second intermission, it was McDavid who sprung in on a breakaway and tucked in his 21st of the season around the outstretched Price off the feed from Draisaitl waiting with the one-touch pass.
After Draisaitl's counterpart hit 60 points, an assist on the play was enough to elevate the German to the same plateau.
Max Domi brought the Canadiens back level, but another duo in Archibald and Sheahan, who've done it all season on the penalty kill, combined offensively on their own 2-on-1 to put the Oilers back in front for the fourth time.
"The importance they have not just on the penalty kill, but in a checking role tonight where it's a tough turnaround coming back at five o'clock the next day, you need everybody throughout your lineup to chip in," Head Coach Dave Tippett said. "The work they put in, we needed that right through our lineup and those guys epitomize that."
The roars of the Oilers fans echoed loudest at the final buzzer after jockeying for decibel supremacy for the entire 60 minutes with the well-travelled Montreal supporters.
"It was a good atmosphere," Sheahan said. "Obviously, Canadian teams travel well and they always seem to have a lot of fans in the crowd. So tonight especially, there were a lot of momentum turns. It was a fun game to play in."
Mikko Koskinen made 23 saves on 26 shots to improve to 13-6-2 on the season.
"It's a huge win for us," the Finnish netminder said. "We really needed it, and it was great to see the home fans supporting us today really well. It was a great atmosphere in the rink, so it was also a big win for them as well."
A date with the Vancouver Canucks on Monday concludes the Oilers schedule before the Christmas break, with the first Battle of Alberta of the season at Rogers Place beckoning on December 27.