"We didn't get frustrated, we just settled down," said Howard, who earned his NHL-leading 17th road win. "I thought we played another great game minus the first five minutes of the third period."
Datsyuk scored the go-ahead goal late in the third, one night after he netted the overtime winner to beat Edmonton. The Red Wings have won two straight after a season-worst four-game losing streak.
"Pavs made a great play," said Justin Abdelkader, who added an insurance goal late in the third. "He's one of the best players in the league and he's been playing so well of late."
Datsyuk added an assist and has 10 goals and seven assists in 17 games since returning from a broken wrist that sidelined him for 19 games.
Howard, who was in net for a 2-1 overtime victory over the Edmonton Oilers at home on Friday, is 17-3-2 on the road. David Backes and Matt D'Agostini scored in a span of 2:31 to tie it but Howard stopped St. Louis' last eight shots.
The Red Wings won 4-3 in overtime in St. Louis on Jan. 20 in similar fashion, blowing a 3-0 lead in the second period before regaining their footing.
Detroit appeared to be in control after two periods, leading 3-1 and holding the St. Louis power play to three shots in four opportunities. After Backes and D'Agostini scored in a span of 2:31 to tie it at 6:19, Red Wings coach Mike Babcock called timeout.
"We got on our heels a little bit. I look up and they scored two goals," Babcock said. "You just need someone to hang onto the puck and make a play."
St. Louis, 0 for 9 on the power play the last three games, threatened only on Patrik Berglund's chance from the slot with about 5 seconds to go in the first period.
"I thought their penalty kill outefforted, outworked our power play," Blues coach Davis Payne said. "We didn't make very clean decisions, and in contact situations they won most of them, either physically or with the stick."
On the Blues' first shot of the final period, Backes scored from the left circle off a feed from Andy McDonald after shooting wide from his knees seconds earlier. D'Agostini's 15th goal came on a deflection of Kevin Shattenkirk's point shot.
Then the momentum switched back to Detroit.
Datsyuk skated around three defenders on the go-ahead goal after winning a battle for the puck along the boards, beating Jaroslav Halak at 13:13. Abelkader added his fifth, beating the St. Louis defense in transition 1:20 later.
"Turnovers to players like that, it usually ends up in our net," Halak said. "It was a learning game for us. Let's not get distracted or anything, just get ready for the next one."
Adam Cracknell's first NHL goal, scored on a one-timer midway through the first period, gave the Blues their only lead. The Red Wings answered with goals 16 seconds apart by Ruslan Salei and Darren Helm.
Salei capitalized on Alex Pietrangelo's giveaway in the slot, scoring unassisted for his second goal of the season and first point in 14 games at 11:51. Helm, who beat the Blues with an overtime goal in January, got his 11th on a rebound for the lead at 12:07.
Blues public address announcer Tom Calhoun worked his 1,097th consecutive game, dating to 1987. ... Red Wings C Mike Modano played in his 1,487th game, tying Wayne Gretzky for 15th on the NHL career list. ... McDonald has four goals and four assists in five games. ... Blues D Nikita Nikitin left because of an undisclosed upper body injury in the first period.