Pittsburgh had scored two goals or fewer in its previous three contests and had been held to no more than two in the past four road games.
"It's big," said Crosby, who was injured in the Penguins' previous game but had two assists against the Blues. "You want to make sure your confidence level is there, and I think we had it.
"It's just a matter of making sure we're focused on playing 60 minutes, especially in this league."
Penguins coach Michel Therrien gave his captain Crosby a lot of the credit.
"You're not going to score six goals in this league every night," he said. "But I thought Crosby's line really set the tone. I thought Sid was really good for a guy who was questionable about playing."
Pittsburgh had not won in St. Louis since beating the Blues 4-3 on Dec. 12, 1998. The Penguins had not played in St. Louis since Dec. 13, 2005 when they lost 3-0.
"It was a big road win for us," Crosby said. "It was nice."
"To win in this league, you need 20 guys on edge, being intense, being urgent for 60 minutes a night," Blues forward David Backes said. "We probably have about 12 [players] for 40 minutes a night. When you have not everyone going for the whole game, you get ugly losses."
The Blues went 3-4 on their seven-game homestand and are 5-5 after a 4-1 start.
"I don't know where we are as a team," Blues coach Andy Murray said. "How do we gauge it? That's a bit of a concern right now."
Trailing 2-1 entering the second period, the Penguins scored three times to take command.
Goligoski tied it 6:03 into the period when he skated in from the point and beat goalie Chris Mason with a wrist shot from the high slot.
With the Blues' Eric Brewer off for holding, Malkin gave the Penguins the lead with a one-timer from just inside the blue line at 12:22. Kennedy made it 4-2 just 37 seconds later when he swatted his own rebound past Mason from a bad angle.
St. Louis entered the game averaging 23.9 shots per game, the fewest in the league. The Blues had four in the first period, but scored on two.
Jackman made it 1-0 just 9:29 in when his shot from the left point deflected off Pittsburgh defenseman Rod Scuderi and past goalie Marc-Andre Fleury. After Satan tied it with a wrist shot at 17:47, Oshie gave the Blues the lead again when he scored off a centering pass from David Perron 17 seconds later.
Ruslan Fedotenko left the Penguins' morning skate with an undisclosed injury and was scratched from the lineup. ... The Blues sent G Marek Schwarz back to Peoria (AHL) and recalled Chris Holt. He is the fifth goalie to dress for St. Louis and he will serve as the backup to Mason until Manny Legace returns. ... Pittsburgh placed Pascal Dupuis on the injured list with an undisclosed ailment and recalled forward Janne Pesonen from the Wilkes-Barre/Scranton (AHL). ... Blues No. 1 draft, D Alex Pietrangelo, returned to the lineup after missing six games with an upper body injury. ... Oshie was injured during a faceoff midway through the second period. He limped off and didn't return.