"I didn't want the same thing to happen twice," he said. "You know ... seconds left, and it's 6-on-3. I kind of felt the same way as last night."
Ilya Kovalchuk scored his 16th goal, and Lehtonen stopped 37 shots to give the Atlanta Thrashers a 1-0 victory over the Florida Panthers on Saturday night.
Coming off a 3-2 loss in a shootout Friday at Tampa Bay, Atlanta won for the second time in three games.
Lehtonen, who allowed Dan Boyle's tying goal with 11 seconds left in regulation the night before, made 12 saves in the third period.
The Thrashers' goaltender improved to 4-0 against Florida this season after Panthers centre Stephen Weiss missed the net on a wide-open shot from the right side with four seconds left in the game.
"It seems like he's playing well against us," Florida captain Olli Jokinen said. "I guess he was in a little slump. I guess he's back on track tonight. In my mind he's a topflight goalie in this league, and the scary thing is he's just going to get better. I give him credit. When you take close to 40 shots, you should be able to score a goal."
Weiss' nine-foot attempt came after Joe Nieuwendyk beat Bobby Holik on a faceoff that began a three-man advantage for Florida.
"They had a pretty good chance with the pass across," Lehtonen said, "but it turned out to be a bad shot."
The Panthers, who have lost three straight and six of eight, failed to take a shot on goal in the final nine seconds of the game even though Atlanta's Brad Larsen and Kovalchuk were sitting in the penalty box.
Panthers coach Jacques Martin had pulled goalie Alex Auld, who stopped 27 shots, with 52 seconds left.
"We're just cutting it way too close," Holik said. "We play all year straddling this fine line between winning and losing. In the long run, it's not going to work."
Despite entering with the NHL's second-best power-play unit, the Panthers dropped to 1-for-23 against Atlanta after failing on seven chances.
"There were some second chances and rebounds," Jokinen said. "The puck is not bouncing our way right now."
Kovalchuk was inside the blue-line when he skated past Bryan Allen for a breakaway. Taking Scott Mellanby's pass from the right boards, Kovalchuk fired a long wrister between the circles to Alex Auld's glove side 13:43 into the first period.
In four games against the Panthers this season, Kovalchuk has seven points, including five goals.
"I don't care who we play against," Kovalchuk said. "I just want to get two points (in the standings) for our team."
Lehtonen had lost his last four starts, but the No. 2 overall pick of the 2002 draft got his third shutout of the season and sixth of his career.
"I knew back in my head that I can play well, and it hasn't been going my way for the last month or so," Lehtonen said. "It was a very frustrating time. Hopefully, I can keep playing well from here on. I just need to keep working hard."
Atlanta's penalty killing delighted coach Bob Hartley.
"Even though Kari made some big saves, I don't think we were in trouble at any point on our penalty kill," Hartley said after earning his 300th career victory. "That was a big reason we got the two points tonight. Five points out of six against three division opponents is a pretty good week."
Notes: Florida dropped to 2-7-3 on the road. ... Early in the second period, the goal light went on, but the officials called for a replay that confirmed Lehtonen ended the play by smothering the puck before it went into the net. ... Atlanta improved to 13-3-2 when Kovalchuk has a point. ... Hartley won 193 games with Colorado, which he led to the 2001 Stanley Cup title.