ST. LOUIS -- Kevin Shattenkirk didn't know if the puck was tipped or not. The defenseman didn't care much, either.
The bottom line for Shattenkirk and the Blues was that his shot helped them win a hockey game.
Shattenkirk's wrist shot from the right point got through traffic at 10:52 of the third period. Penguins goalie Marc-Andre Fleury got a piece of the puck but it trickled into the net to break a 1-all tie.
"It was a great play," said Shattenkirk, who extended his point streak to eight games. "Our forwards did a great job keeping the puck alive. Get a D-to-D pass from (Barret Jackman) and throw it to the net.
"We still don't know" if the puck was tipped by Vladimir Tarasenko, who was screening Fleury. "We think someone might have tipped it, but for now, I'll take it."
Ryan Reaves also scored for St. Louis and Jaroslav Halak stopped 19 shots as the Blues won for the 11th time in 15 games to start the season. It's the first time they've done that since 2003-04, also the best start in franchise history.
"I think Pittsburgh's competitiveness made us play 60 minutes," Blues coach Ken Hitchcock said. "I thought we got stronger and stronger as the game went on. Our third period was our best. Our second was awfully good, too."
It was St. Louis' first regulation victory against the Penguins since a 4-1 win Dec. 19, 2006, in Pittsburgh.
"I thought we played a really smart, strong, hard hockey game. Both teams competed at a very high level," Hitchcock said. "It was a playoff game and we scored the big goal in the third period, but we played a heck of a third period."
Jussi Jokinen scored and Fleury made 30 saves for the Penguins, who have dropped two straight after a four-game winning streak. The 20 shots were a season low for Pittsburgh.
"They are probably the best in the league playing this defensive-minded, checking game," Jokinen said of the Blues. "We still generated enough chances to score three or four goals, but we didn't bury those chances."
Reaves scored the first goal of the game and the 11th of his career when he redirected Maxim Lapierre's centering feed past Fleury 2:52 into the second period.
"I don't think anyone really knew I was coming on the ice," Reaves said. "It was a late change. He had some good patience to see me backdoor and just a great pass."
The Penguins were able to get the equalizer when Jokinen, parked in the slot, redirected Evgeni Malkin's centering feed from the right circle 8:06 into the second. Roman Polak was serving an interference penalty for the Blues.
"The game was almost as expected -- the tightness of the game and the matchups," Penguins coach Dan Bylsma said. "There wasn't a lot out there."
Shattenkirk and Chris Stewart gave the Blues their best scoring chances in the first period. Shattenkirk's shot from the right circle was stopped by Fleury 5:33 into the game. Stewart missed on a backhand at the side of the Pittsburgh net after getting a pass from Patrik Berglund with 8:33 left in the first period.
Halak was up to the task for the Blues in the first, stopping Chris Kunitz's one-time snap shot of Sidney Crosby's no-look pass with 10:17 remaining. Halak then had Crosby barreling down on him from the left side after T.J Oshie's turnover, but the Blues' goalie made a save with his right arm as Crosby tried going high on the short side with 3:45 remaining in the opening period.
Fleury preserved a 1-all tie by stopping Oshie with 16:15 remaining, then getting a shoulder on David Backes' one-timer after Oshie's feed with 10:45 to play.
Fleury flashed his glove on Alexander Steen's wrister with 5:14 left off a 2-on-1 to keep the Penguins within a goal at 2-1.
But he lamented the fact that he didn't see Shattenkirk's shot get through.
"I don't know. I've got to see it again," Fleury said. "Who got the goal? Was the guy in front? I want to see it again."
The Blues don't care. All that mattered to them is that it went in.
"We'll see when we wake up tomorrow," Shattenkirk said. "Either way, it was a good effort there by everyone to open up that opportunity. I think the hard work that we had through the entire third period is what led to that goal."
The Blues are one of four teams that haven't allowed a goal to Crosby in his career. The others are San Jose, Edmonton and Chicago. ... Blues D Jordan Leopold (hand) missed his first game of the season. Penguins D Paul Martin (undisclosed) also missed his first game with an injury. Penguins RW James Neal (upper body) returned after missing 15 games. RW Beau Bennett (lower body) returned after missing 11 games. ... The teams' previous meeting was Jan. 24, 2012, a 3-2 shootout victory for the Penguins. ... Reaves and Penguins D Deryk Engelland fought 3 seconds into the game.