Smolinski scored twice, Carey Price came within 8:30 of posting his second straight shutout, and Montreal beat Buffalo 3-1 on Thursday night, eliminating the Sabres from the playoff race.
Chris Higgins opened the scoring with a power-play goal midway through the first and Smolinski added two more goals to give the Canadiens a 3-0 lead.
"They had to go for it and I think they played a little cautious at first and, I won't say they played into our hands but getting the first one was huge," Smolinski said. "It kind of deflated them a little."
Montreal is tied with Pittsburgh atop the Eastern Conference with 102 points. Both teams have one game left but the Canadiens need to finish at least a point ahead of the Penguins to win the conference because Pittsburgh has 47 wins, one more than Montreal.
The Canadiens host Toronto on Saturday night. The Penguins complete their season Sunday in Philadelphia.
"We've got one more game and then we can regroup and get ready," Price said. "One last game to get everything into gear before we hit the crucial time of the year."
"We gambled hard to get back in it and we just didn't quite get it done," Ruff said.
The Sabres, who won the Presidents' Trophy last year and went to the conference final each of the last two seasons, needed at least one point to keep slim playoff hopes alive.
"They got the first break and we had to play catch-up," said Miller, who stopped 22 shots.
Buffalo, which has 88 points, completes its schedule Saturday in Boston and is assured of finishing 10th overall in the East.
"You could see their faces after the game," Higgins said. "Obviously, they weren't too thrilled."
Named the NHL's rookie-of-the-month for March, Price made 27 saves and improved his record to 23-12-3 in 40 games. The 20-year-old goalie stopped 32 shots Tuesday as the Canadiens clinched their first division title in 16 years with a 3-0 win in Ottawa.
Montreal struck quickly midway through the first, scoring two goals in 40 seconds to take a 2-0 lead.
Higgins opened the scoring on a power play 11:28 in when he beat Miller for his 25th goal.
The soldout Bell Centre crowd of 21,273 was still celebrating the Canadiens' opening goal when Smolinski made it a two-goal lead with his seventh of the season at 12:08.
The 36-year-old veteran scored his second of the game -- his eighth overall in 63 games -- 14:28 into the second to increase Montreal's lead to three.
- The Sabres last missed the postseason in 2003-04.
- The Canadiens last won a conference title in 1988-89. They finished atop the Wales Conference with a 53-18-9 record and went on to lose a six-game final to the President's Trophy-winning Calgary Flames, the last time the league's Nos. 1 and 2 teams met for the Stanley Cup.
- Canadiens RW Matt D'Agostini made his NHL debut. D'Agostini, chosen 190th overall by Montreal in 2005, was recalled from Hamilton of the AHL on Wednesday along with LW Gregory Stewart, who did not dress.