ST. LOUIS -- The St. Louis Blues have four lines rolling, they're minimizing mistakes, especially in the defensive zone, and most importantly, they're healthy.
The Blues also defeated the Sharks 7-2 on Jan. 3.
Lehtera, Steen, Oshie, Backes and Paul Stastny each had a goal and an assist. Schwartz had three assists, and Tarasenko two.
The Blues (25-13-3) have won three in a row, outscoring their opponents 20-4.
"The first 12 minutes was just a continuation of the way we played on the road pretty much. We were dialed in," Blues coach Ken Hitchcock said. "We actually looked the same. There was good energy, good focus, really unselfish hockey. Unselfish hockey, for me, is what's really evident right now. A lot of things we're doing, the team play aside, when you're unselfish, you come off the ice at the right time, you change at the right time, you leave your teammate in a good spot, you're going to have success.
"To me, the goals are a result of the way we're playing. We're playing the right way, and it's having a big impact on keeping the group together."
The Blues, known for being defensive-minded, have scored six or more goals in three straight games for the first time since Dec. 9-15, 2000.
"Not since I've been here, no I haven't [seen it]," said Oshie, who has a career-high seven-game point streak (six goals, seven assists). "But without scoring the goals, if a couple of those go off the post and out, we're still playing great hockey, we're still getting pucks deep, we're still working for each other.
"We'll take the goals, but I think that's what we'll take out of these games."
St. Louis, which has the NHL's top-ranked power play at 26.4 percent, went 2-for-4 with the man advantage Thursday. The Blues have scored seven power-play goals during the three-game winning streak.
Logan Couture had a goal and an assist for the Sharks (22-15-5), and rookie Melker Karlsson scored to extend his goal streak to four games. Antti Niemi made 16 saves on 21 shots before being replaced by Alex Stalock in the second period after the Blues' fifth goal.
"You can sit here and make every single excuse in the book, but to lose 7-2 is unacceptable with this team that we have," Couture said. "We just got beat, plain and simple, again, by that team.
"We're better than what we've shown. To go out and play that team two games and get spanked like that ... we haven't been good in front of our goalies against these guys."
Steen opened the scoring with his 11th goal, extending his point streak to five games (three goals, eight assists).
St. Louis took off in transition after goalie Brian Elliott, who made 24 saves to earn his third straight win, denied Couture on a shorthanded chance. After two cross-ice passes, the second from Tarasenko, Steen put a wrist shot past Niemi from the right circle at 10:38 of the first period.
Jay Bouwmeester's first goal in 22 games gave the Blues a 2-0 lead. His wrist shot from the left point beat Niemi through a Schwartz screen at 15:06 of the first.
With Joe Pavelski serving a double minor for high sticking against Tarasenko, the Sharks got back in the game when Couture converted a 2-on-1 shorthanded rush, this time beating Elliott with a quick snap shot from the left circle with 1:33 remaining in the first.
But Stastny's ninth goal put St. Louis back ahead by two with 54 seconds left in the first. It was Stastny's ninth point in seven games, and the Blues' second power-play goal on three tries in the opening period.
The Sharks again cut the Blues lead to one when Karlsson scored 29 seconds into the second period. Karlsson batted in a rebound after Couture's shot bounced off Elliott's glove.
Lehtera and Oshie each scored to give the Blues a 5-2 lead after two periods.
Lehtera's first goal in nine games came off a nifty seam pass from Schwartz. He beat Niemi at 8:52 to make it 4-2.
Oshie knocked in a rebound of a Steen shot at 13:20 to chase Niemi.
Patrik Berglund's wraparound goal, off a pass from Stastny, at 9:05 of the third period gave the Blues a 6-2 lead.
Backes scored his fifth goal in two games on a slap shot from the slot off Schwartz's third assist of the game. His shot deflected off Sharks defenseman Marc-Edouard Vlasic's stick over Stalock, who made five saves, at 11:59 to make it 7-2. It was Backes' 10th point in seven games.
The Blues have had scoring streaks from individual lines throughout the season, but this is the first time they've had three lines consistently scoring.
"You look at the Stastny group (with Dmitrij Jaskin and Berglund), they've been going very hot lately," Hitchcock said. "The first 10 games, it was Lehtera. You look at the third packet, it was Lehtera's group. We've never had both groups going, but there's always been one group that's been really focused, energized and carrying us. I find that really unique. The trade-off between one group that's struggling and the other group that seems to be picking it up. That's what to me has kept us at a high level."