The Senators, Rangers and New York Islanders each have 54 points; Ottawa is sixth because it has a game in hand on the other two; the Rangers are seventh because they own the tiebreaker with the Islanders.
The Islanders, who will be making their first playoff appearance since 2007, dropped from sixth to eighth by losing 2-1 to the Philadelphia Flyers. New York ends its season Friday on the road against the Buffalo Sabres and needs a point to have a chance to finish anywhere higher than eighth.
The Rangers play host to the New Jersey Devils on Saturday afternoon; Ottawa is home to Philadelphia on Saturday night and visits the Boston Bruins on Sunday in the 720th and final game on the NHL schedule.
Here's a look at the potential scenarios for the Eastern Conference Quarterfinals:
The Pittsburgh Penguins have locked up first place in the East and can rest their regulars in their season finale against Carolina on Saturday. The Penguins will face the lowest finisher among the Senators, Rangers and Islanders.
The Boston Bruins and Canadiens each have 61 points after victories Thursday, but the Bruins are first in the Northeast Division because they have two games remaining to one for the Canadiens. The division champion gets the second seed and will face the middle finisher among the Senators, Rangers and Islanders; the second-place team will end up fourth in the conference and will have the home-ice edge in the opening round against the Toronto Maple Leafs.
The Washington Capitals are locked into third place as the Southeast Division champions. They will face the top finisher among the Senators, Rangers and Islanders.
The Toronto Maple Leafs saw their hopes for home ice end when the Canadiens defeated the Jets, 4-2. That eliminated the Maple Leafs' hopes of catching the Canadiens by beating them in their season-finale Saturday night at Air Canada Centre. If the Maple Leafs do win that game and the Bruins get one point in their last two contests, Toronto and Montreal would meet in the playoffs for the first time since 1979.
The Senators control their fate. If they can defeat the Flyers and Bruins, they'll most likely face the Capitals in the opening round. That could be a good matchup for the Senators, who swept the season series. Two wins and a Toronto regulation loss to Montreal would get them up to fifth.
There was a sense of relief on the bench of the Rangers when Ryan Callahan scored the overtime winner, assuring New York of its third playoff berth in four seasons. The Rangers have one more regulation win than either the Islanders or Senators; if New York can defeat New Jersey at Madison Square Garden, they'll finish no worse than seventh and will end up sixth unless Ottawa gets at least three points in its final two games.
The Islanders entered Thursday with hopes of ending up in fifth place. To avoid finishing eighth, they need at least a point Friday and losses for the Senators and Rangers.