Midway through December, the Atlanta Thrashers held sole possession of first place in the Southeast Division while the New York Islanders had lost 21 of 23 games.
Both clubs have since drifted towards mediocrity.
New York hosts Atlanta on Wednesday night in a matchup of teams likely to miss the Eastern Conference playoffs.
The Thrashers (30-30-12) claimed the Southeast lead Dec. 18, appearing poised for the franchise's second playoff berth in its 11-season history. Since then, Atlanta has lost 26 of 38 to fall nine points behind Buffalo for eighth place in the East.
The Thrashers had gone 4-1-1 in their previous six games, but then allowed their second-most goals of the season Saturday in an 8-2 road loss to the Sabres to begin their two-game trip to New York State.
"We pitched a stinker," forward Anthony Stewart said. "We can't really dwell on it and let it be the turning point of our season. Every game's a must-win, so we'll regroup."
Ondrej Pavelec, who allowed three goals for the fifth straight start, was pulled after giving up all three on 11 shots in the first period. Chris Mason didn't fare much better, allowing five goals on 17 shots.
"We allowed our frustration to take control of the game," coach Craig Ramsay said. "We have to play with pride."
Captain and leading scorer Andrew Ladd is scoreless with a minus-7 rating over his last three games. Dustin Byfuglien, once considered a contender for the Norris Trophy as top defensemen, doesn't have a point in his last four games and has just three goals since Jan. 5.
While the Thrashers have regressed to the .500 mark, the Islanders have been playing much better recently.
Atlanta handed New York two losses during a dismal 1-17-3 stretch from Oct. 23-Dec. 13, but the Islanders (29-33-12) have surged since the All-Star break. With a regulation win Thursday, they can tie the Thrashers in the conference standings.
New York is 14-6-5 since Feb. 1 - when it won 4-1 at Atlanta - and has won two straight including a 5-2 victory Tuesday at Tampa Bay. Frans Nielsen scored his NHL-leading sixth short-handed goal for the Islanders, who wrapped up a 2-1-2 road trip.
"We go out and we compete hard for 60 minutes and try to have fun," Nielsen said. "Everybody is chipping in for the team right now."
Kyle Okposo, who had two goals an assist in the most recent meeting with the Thrashers, scored for the first time in nine games. Al Montoya made 36 saves to beat the Lightning and improved to 8-3-4 with a 2.37 goals-against average.
"Our goal was to come in here and play our best game," said Montoya, who has never faced Atlanta. "I give it to our team, though. They fought for me and they battled. They didn't let them knock us down, and that just motivated me to play harder. It feels great right now."
Atlanta beat New York 2-1 at home Nov. 21 when Byfuglien scored in overtime, then won 5-4 on Dec. 11 on Long Island. Thrashers defenseman Johnny Oduya scored his only two goals of the season in that contest.