The 31-year-old Budaj was on the top of his game despite playing in place of No. 1 goalie Carey Price for only the second time this season and first since Oct. 10 at Edmonton when he stopped 27 of 28 shots in a win.
Plekanec scored the decisive goal on a power play in the second period. Budaj made it stand up for Montreal (7-5), which had lost three of four since a four-game winning streak.
Galchenyuk scored his second goal of the season with 2:51 left. That sealed the win moments after Budaj blocked an in-close chance for Mats Zuccarello.
STARS 4, SABRES 3
BUFFALO, N.Y. (AP) — Tyler Seguin capped a three-goal, first-period outburst, and the Stars hung on to deliver coach Lindy Ruff a win in his homecoming against the Sabres.
Jamie Benn, Alex Goligoski and Vernon Fiddler also scored in a game the Stars nearly squandered a 4-1 lead against the NHL's worst team. Eric Cole added two assists in Ruff's first game against his former team after his 16-year tenure in Buffalo ended with him being fired on Feb. 20.
Matt Moulson nearly spoiled Ruff's return by scoring two goals in his Sabres debut, a day after being acquired in a trade the sent Thomas Vanek to the New York Islanders. Steve Ott also scored for Buffalo (2-11-1), which matched its worst start through 14 games.
BLACKHAWKS 5, WILD 1
ST. PAUL, Minn. (AP) — Patrick Sharp finally scored, Nick Leddy jump-started Chicago's stagnant special teams with a power-play goal and the Blackhawks beat the Wild.
Corey Crawford made 29 saves, and Sheldon Brookbank, Patrick Kane and Brandon Saad all scored to give the Blackhawks just their third game of more than three goals in 12 contests this season.
After giving up 11 goals while losing their previous two games, the Blackhawks played tougher defence, were more disciplined and paid the Wild back for their 5-3 win Saturday in Chicago.
Jason Pominville had a goal for the Wild, his third in two games to tie it at 1 midway through the second period, but Niklas Backstrom never found his footing in the net.
PENGUINS 3, HURRICANES 1
RALEIGH, N.C. (AP) — Rookie Jayson Megna had his first career goal and assist, and the Penguins snapped a three-game losing streak by beating the Hurricanes.
Chris Kunitz and Tanner Glass also scored for the Metropolitan Division-leading Penguins. Brooks Orpik had three assists, Sidney Crosby added two and Marc-Andre Fleury stopped 20 shots.
Pittsburgh ended its longest losing streak since 2011-12 by defeating the Hurricanes for the fourth straight time.
Nathan Gerbe scored a power-play goal for Carolina, which lost its third straight but remained tied with the New York Islanders for second in the division — five points behind the Penguins. Justin Peters made 26 saves in his second straight start in place of the injured Cam Ward.
CANUCKS 3, CAPITALS 2
VANCOUVER, British Columbia (AP) — Daniel Sedin scored the game-winner in the third period and added an assist for Vancouver, which won its fourth straight.
Zack Kassian and Ryan Kesler also scored for Vancouver, which played at Rogers Arena for the first time since Oct. 12 after a seven-game trip. Henrik Sedin added an assist to extend his point streak to nine games.
Roberto Luongo made 17 saves for the Canucks.
Jason Chimera, with a goal and an assist, and Mikhail Grabovski scored for Washington, which got 38 saves from Michal Neuvirth.
After the teams traded goals early in the third period, Daniel Sedin and Henrik Sedin played keepaway in the Washington zone to give Vancouver the lead for good. Daniel Sedin finished the sequence off by faking a pass at the top of the slot and blasting a shot past Neuvirth at 5:01 to make it 3-2.