"We can't mistake what we're doing here for being great," Renney said after New York improved to 10-2-1. "We've had moments of greatness in every game, but it's about sustaining that."
Nikolai Zherdev had a strong third period, driving to the net to score the Rangers' first go-ahead goal of the frame and then assisting on Dan Girardi's winner with 6:27 left after nearly putting the puck in on a wraparound.
Markus Naslund added a first-period goal, enough to give the Rangers their fourth straight victory. The 10 wins and 21 points are the best for New York through 13 games.
"Obviously we are very confident going into the third period when it's a close game," said Henrik Lundqvist, who made 27 saves and earned his NHL-leading eighth win.
Kari Lehtonen bounced back from Atlanta's 7-0 home loss to Philadelphia on Tuesday, in which he allowed all the goals on 31 shots. He finished with 30 saves, but the Thrashers (2-6-2) dropped their fourth consecutive in regulation and fifth overall (0-4-1).
"At least we gave ourselves a chance to win," Thrashers coach John Anderson said. "A loss is still a loss. It's two points whether it's 6-0 or 3-2. We have to start finding ways to win. We don't want to find ourselves so far behind the eight-ball we can't climb out of the deep hole we're digging."
Slava Kozlov gave Atlanta a 1-0 lead in the first and Bryan Little tied it in the third. Todd White had two assists.
Anderson didn't blame Lehtonen for the blowout loss, citing that four goals went in off legs. He gave his No. 1 goalie his ninth start in 10 games and said he was pleased with his overall play.
"That's the best thing about hockey," Lehtonen said. "You have the chance pretty soon to get your game back. I felt good all night and I was quick."
Atlanta made it 2-2 during a power play at 10:28 when White found Little alone in front. With Lundqvist sprawled on his stomach, Little lifted a shot over him for his fifth goal.
The Rangers took the lead 3:30 earlier on Zherdev's power-play goal. Zherdev took the puck after defenseman Tobias Enstrom's pass hit the skate of teammate Colby Armstrong near the right-wing boards.
He worked the puck back and forth on his stick as he closed in on Lehtonen, then snapped a backhand that somehow squeezed under the crossbar and popped up the water bottle.
"He's so good with the puck," Lehtonen said. "It looked like he was going to go all the way to the other side, but he was able to put it up very quickly before I even knew it. He's just one of those guys that you don't want to let alone in front of the net.
Usually something bad happens."
Naslund, who extended his point streak to five with a first-period goal, thought he had given the Rangers the lead during a power play 30 seconds into the middle period. Naslund got to a rebound of his shot, turned his right foot and skated into the puck - knocking it past Lehtonen. The goal was waved off after a video replay.
That began a string of three straight power plays for the Rangers, who had a pair of fruitless 5-on-3 advantages before the second period was 3 minutes old. The first lasted 1:12, compared to 3 seconds for the latter. All three power plays ran off with frustrated fans at Madison Square Garden imploring the Rangers to shoot. New York didn't record a shot while skating with a two-man advantage.
"The power play might be the simplest thing to play on the ice," Renney said. "We find a way to make it hard."
Atlanta nearly grabbed the lead while short-handed when White escaped a pack of Rangers and raced on a breakaway. White was chased by Zherdev, who caught him with a full-body dive and knocked the puck away with a swipe of his stick.
"I just work for the team," Zherdev said, "that's it."
The Thrashers, who recorded only 14 shots through two periods, took a 1-0 lead 4:41 in on Kozlov's fourth goal.
Naslund tied it 7:44 later with his fourth.
Notes: The Rangers traded disappointing forward Hugh Jessiman to the Nashville Predators for future considerations. Jessiman, taken with the No. 12 pick in the 2003 draft, never played a regular-season game with New York. ... White leads the Thrashers with nine points and seven assists. ... Thrashers D Zach Bogosian, the No. 3 pick in this year's draft, missed his first game after breaking his left leg against Philadelphia. ... Naslund has three goals and four assists during his streak.
