Two weeks ago, the Philadelphia Flyers appeared to have a lock on first place in the Patrick Division of the National Hockey League and some people even gave them a chance of regaining the Stanley Cup. At the same time, the slumping Atlanta Flames were fighting just to qualify for the playoffs in that division.

But after Atlanta's 4-1 win over the Flyers Thursday night, in which the Flames' Phil Myre put on an outstanding display of goaltending, the outlook for both teams changed dramatically.

Atlanta, which had won but four of 20 games and held a slim two-point lead over the New York rangers before their two-game showdown last weekend, went nine points up on the Rangers Thursday in the battle for the third and final playoff spot by winning its fourth straight game.

At the other end of the spectrum, the Flyers,who led the New York Islanders by eight points with a game in hand less than two weeks ago, suffered their third loss in five home games and now maintain a scant three-point lead as they begin a three-game road trip to Los Angeles, Vancouver and Boston.

"What can you do ?" asked Philadelphia coach Fred Shero. "it's not good. We got a couple of guys not playing and a couple of guys hurt. I don't know what it it."

Despite his team's streak Atlanta coach Fred Creighton is approaching the Flames' remaining eight games with guarded optimism.

"I feel more confident (of a playoff berth) now than I did at 8 o'clock to-night," Creighton said. "But looking at their (the Rangers') schedule, they could win at least five games between now and the end of the season."

When informed that the Flames would only have to win one more game if the Rangers won five of their reaining contests, Creighton replied, "well, we'd have to win that game before I'd feel comfortable."

Eric Vail snapped a 1-1 tie with his 30th goal of the season 26 seconds into the second period. The Flames added third-period goals by defenseman Dave Shand and Curt Bennett and got a first-period score from Ken Houston. The acrobatic Myre, who stopped 28 shots, allowed only a first period goal to Curt's brother, Harvey.