"Finally, we put some goals on the board and it's a great feeling all around," said Perry, who was credited with his second assist -- at Getzlaf's expense -- in a scoring change to Anaheim's sixth goal after the game.
"When you do have 50 shots you have to bury a lot more of those," Tanguay said.
The Canadiens, who hosted their 2,900th NHL regular-season home game, failed to record a point for the first time in seven games (5-1-1).
"We did some good things but the mental focus wasn't there," Koivu said. "We weren't as sharp as we were used to being in the last couple of games here."
Huskins and Getzlaf scored 2:51 apart to give the Ducks a 2-0 lead early in the first period.
Montreal answered with three straight goals, beginning with Tanguay's fourth of the season on a power play midway through the first.
Koivu scored his fourth goal just as Todd Marchant's tripping penalty expired with 3:37 left in the first, and Kostopoulos put the Canadiens up 3-2 with his first goal of the season 1:34 into the second.
Anaheim came back with three straight goals before the end of the middle period.
"Even though they scored the two goals to tie the hockey game and then they went up 3-2, we didn't really stray away from what we were trying to do," Ducks coach Randy Carlyle said. "We were fortunate enough that our goaltender made enough stops at critical times and our power play delivered for us."
Perry scored his first of the season on a power play at 2:40 to even it at 3, and Kunitz restored the Ducks' lead with his first at 4:40, chasing Jaroslav Halak, who allowed four goals on 12 shots.
Moen scored a short-handed goal with 3:21 left in the second period when he put a backhand past Carey Price on a breakaway.
Perry was awarded a penalty shot with 1:56 remaining in the second but lost control of the puck when he went to his backhand on Price.
Selanne increased the Ducks' lead to 6-3 on a power play 5:40 into the third.
Tanguay scored his second goal of the game with 6:15 left.
Montreal's Andrei Markov played his 500th regular season game, extending his assists and points streaks to seven games with an assist on Tanguay's first goal.
New Ducks D Bret Hedican, signed as a free agent Thursday, was not in uniform. LW Brad May also was a healthy scratch. ... Canadiens LW Chris Higgins made his season debut after missing the first six games because of a groin injury. ... It was Halak's first career appearance against Anaheim. ... Koivu's points streak reached six games. He has four goals and six assists over that span.