Both played an integral part in snapping that long losing streak on Monday night.
Horvat opened the scoring in the first period before taking a key faceoff on a 6-on-4 penalty kill late in the third, and Lack made 29 saves as the Canucks held on for a 2-1 win over the Ducks.
"I thought the whole team played really well," said Horvat, a 19-year-old rookie, who has gained the trust of coach Willie Desjardins. "The whole team was contributing tonight — goaltending all the way through. We were doing the little things, playing well defensively.
"That was a huge win for us. We need those points."
Zack Kassian scored the winning goal with 3:59 left in the third for Vancouver, which is in second place in the Pacific Division, three points up on the Calgary Flames.
Emerson Etem had tied it for Anaheim at 8:40 of the final period.
"I think it showed the character of our team," said Kassian, who scored his 10th of the season. "We bounced back, and our hardest push was in the third."
The Canucks hadn't beaten the Ducks in regulation since Jan. 13, 2013. Vancouver also handed Anaheim its first one-goal loss in regulation this season.
"I'm feeling good right now, I'm not going to lie," Lack said. "It's fun playing right now, playing these hard games, tough games. I feel like everyone is standing up for each other. It's a huge team game right now."
Vancouver had just 10 shots through two periods, and managed six more in the third on Frederick Andersen, but the Canucks made their few chances count.
"They're a tough team. I think we played hard all night," Desjardins said. "You just don't generate a whole lot against them. I thought the guys were focused right from the start. I thought we had lots of energy.
"I think whenever you play them you're going to have a battle. You look at all their one-goal games, that's just how they play."
Anaheim (42-19-7) is tied with Nashville atop the NHL standings. The Ducks, who were 26-0-7 in games decided by one goal, lost their second straight after winning four in a row.
"You don't like to lose at all, but they took advantage of a mistake we made, and we don't make a lot of them," said Ducks coach Bruce Boudreau, whose team was 9-0-1 in its previous 10 against Vancouver. "We felt if we stayed the course we were eventually going to score a goal.
"Once we scored, we let our foot off the gas and they came on a bit and started to play with a little desperation."
After allowing the first goal in six straight games, and having fallen behind 2-0 in each of their last four, the Canucks opened the scoring at 9:57 of the opening period when Horvat jumped on a loose puck in the slot and ripped in his 11th of the season.
It was his second goal in two games.
"You don't want to try to come from behind against that team," Desjardins said. "I thought we responded well. Once they tied it, I thought we came back and started to play hard.
"It was a good effort all the way around."