Vince Dunn scored two goals, and Pat Maroon had one goal and one assist for the Blues (37-27-7), who scored three total goals in three straight losses. They are third in the Central Division, seven points behind the Winnipeg Jets, six behind the Nashville Predators and two ahead of the Dallas Stars.
"We had a lot of emotion," Binnington said. "I think that's important this time of year. We were playing hard for each other."
WATCH: [All Blues vs. Penguins highlights]
Matt Murray made nine saves on 13 shots for the Penguins (39-24-9), whose three-game winning streak ended. Pittsburgh is third in the Metropolitan Division, four points behind the Washington Capitals, two behind the New York Islanders, two ahead of the Carolina Hurricanes and three ahead of the Columbus Blue Jackets.
"I think our mentality has to be a playoff one," Penguins captain Sidney Crosby said. "Sometimes it doesn't go your way. You've got to be able to forget about it."
Murray was pulled at 2:41 of the second period, and Casey DeSmith made 12 saves in relief.
"It's more quality than quantity, I think," Murray said. "They got a few really good chances. I wasn't able to make a save. So I definitely have to be better. As a team, I think we played a pretty good game for the most part. So we have to take the positives from it and forget the result."