Lehtonen made 38 saves for his league-best fifth win, Jamie Benn had a goal and an assist and the Stars hung on for their fourth straight win, a 3-2 victory over the winless Columbus Blue Jackets on Tuesday night.
"He's the last line of defense and he's been our first star in every game," Benn said.
Steve Ott and Michael Ryder also scored for the Stars who seemed in complete control until Kris Russell snuck a shot past Lehtonen to pull Columbus within a goal with just under three minutes remaining.
Then Vinny Prospal nearly tied it in the final seconds, redirecting the puck slowly past the post with Lehtonen leaning the other way.
But it was Lehtonen's superb work in the middle of the game that stood out.
"We turned the puck over four times in the last 10 minutes of the (second) period," Dallas rookie coach Glen Gulutzan said. "They got their flurry of chances from there. That's when Kari was the difference for sure."
Supposedly in rebuilding mode with the NHL's lowest payroll, the Stars have won five of six to start the season.
"It's a lot, lot better than starting off slowly," Lehtonen said. "It's really hard to start climbing back and getting those wins back."
On the other end of the spectrum is Columbus, which had bursts of solid play and outshot Dallas 40-18, but it couldn't stop them from extending the worst start in franchise history to 0-5-1. They are the only team in the Western Conference without a win and have one regulation victory in their last 28 games dating to last season.
"You can hang your head and feel sorry for yourself, but nobody else in the league is going to feel sorry for you so you better keep throwing that effort out there," Blue Jackets coach Scott Arniel said. "You'd think with 40 shots you're going to get more than two. We've got to find a way to get more goals."
To compound matters for Columbus, both of their marquee free-agent signings are on the shelf. Defenseman James Wisniewski has two games left in an eight-game suspension and center Jeff Carter was placed on injured reserved Tuesday for at least a week with a broken bone in his foot.
About four minutes later, Columbus defenseman Aaron Johnson thought he scored with a slap shot from between the high circles but it was ruled teammate Derek Dorsett was in the crease and the goal was disallowed.
Ott opened the scoring at 4:17 of the second period to extend his points streak to five games. After winning the faceoff in his own zone, Ott raced to the other end and fired a shot from the right circle past Mason's glove hand.
Benn stripped the puck from two Columbus players along the boards then cut in on net, scoring with a nifty shot a 1:31 into the third period to extend Dallas' lead.
"It was amazing," Lehtonen said of the goal. "He's so good at stealing pucks."
Later in the period with a man advantage, Brassard scored on the rebound from a shot by Rick Nash for his first point of the season.
But on the next shift after the goal, Loui Eriksson whistled a shot off the post before Ryder redirected Sheldon Souray's shot from the point on Dallas' next scoring chance to make it 3-1 just over a minute later.
"We've done some good things and we've put some periods together, some stretches together," Souray said. "But we've had some where we've sat back and let him (Lehtonen) take a lot of shots. When we have, he's made the saves."
Russell scooped a loose puck off the boards, skated in and beat Lehtonen from the high slot at 17:05.
A string of goalie injuries within the organization forced the Blue Jackets to add Mathieu Corbeil, a 2010 draft pick and fifth on the depth chart, as an emergency recall from the Saint John Sea Dogs (a Canadian junior team) to the gameday roster. ... The Stars, playing the first game of a four-game road trip, improved to 13-4-3 in Nationwide Arena. ... Brassard's goal was the 2,000th in franchise history. ... The teams played Saturday in Dallas with the Stars winning 4-2.