Lehtinen missed 33 games from Nov. 23-Jan. 29 with an abdominal injury. The 12-year veteran right wing has four goals and six assists in the 11 games since his return to the lineup.
"I'm getting there," said Lehtinen, who led the Stars with 26 goals last season. "Spring is the best time for a hockey player. Every game is bigger and bigger."
Dallas missed Lehtinen's two-way game, and they're feeling better about their chances in the playoffs with Lehtinen healthy again.
"He does so many things that are overlooked," Stars captain Brenden Morrow said. "We missed the little things he does, his positioning. Now he's back up to speed. He's got his legs back under him. We really depend on him."
The Stars are 10-2 against the Oilers over the past three seasons and 22-4-2 at home against the Oilers since moving to Dallas in 1993.
Turco improved to 15-4 against Edmonton and helped the Stars win for the 10th time in 12 games overall.
But Mike Modano's empty-netter with 1:59 left, his 17th of the season and 524th of his career, pushed Dallas' lead to 5-2 and closed out the Oilers.
Two of the games between the teams have been close this season, with Dallas winning one in a shootout and another in overtime.
"They've all been close games except this one," Stars coach Dave Tippett said. "They've had injuries to major people and they've gone through some growing pains. But you know they're going to compete hard and make sure you're in the game."
The Oilers have lost three straight overall, allowing 14 goals during that span to further damage their chances of climbing into Western Conference playoff contention.
Edmonton coach Craig MacTavish said his team's chances of winning disintegrated in the second period when Dallas built an 18-7 shots-on-goal edge.
"The second period was an embarrassment for us," MacTavish said. "We had frenetic play in our zone, we took penalties, and we never recovered. We played marginally better in the third period but there wasn't enough composure in our end and they capitalized."
Eriksson deflected Jokinen's centering pass past Edmonton goaltender Mathieu Garon at 16:34 of the first period for Eriksson's seventh goal of the season to give Dallas the early lead.
The Stars grabbed a 2-0 advantage at 5:35 of the second period when Lehtinen capitalized on a power play, redirecting Morrow's pass through Garon's pads.
Morrow scored at 17:13 of the second period on the penalty kill, skating the length of the ice and around Edmonton center Jarret Stoll to match a career high with his 25th goal.
The Oilers had four penalties in the second period, and they couldn't recover.
"We took way too many penalties," Oilers captain Ethan Moreau said. "We didn't get that power-play goal we needed early. Special teams was obviously the difference. We didn't have a lot of composure tonight."
Edmonton made a goalie change after two periods, going with Dwayne Roloson for the final 20 minutes. Roloson hadn't played in the previous seven games.
Lehtinen notched his second goal and 10th of the season when he scored on the second shot Roloson faced at 4:32 of the final period to push Dallas' lead to 4-0.
D Sergei Zubov (groin, foot), D Philippe Boucher (shoulder), and C Stu Barnes (eye surgery) are out for Dallas. ...The Oilers are without LW Raffi Torres (knee), D Sheldon Souray (shoulder), C Shawn Horcoff (shoulder) and D Ladislav Smid (ankle). ...C Jeff Halpern also missed the game for Dallas with a groin injury but he could play in Saturday's game at Nashville.