Ottawa's Andrew Hammond suffered his first regulation-time loss on Thursday as the Senators fell to the New York Rangers 5-1.
"We didn't help him and that was ultimately the difference," Senators defenceman Marc Methot said.
Hammond allowed five goals on 22 shots and is now 14-1-1 to start his NHL career. If the 27-year-old goaltender had pushed the game to overtime, he would have tied former netminder Patrick Lalime by earning at least one point in his first 16 NHL games. Lalime went 14-0-2 in 1996-97.
"You've got to help out your goaltender, especially with Hammer since he's stood on his head for us for so many games in a row," added Methot. "We certainly didn't do him any favours and it showed and we got pumped on the scoreboard."
Chris Kreider had two goals and an assist as New York also put an end to Ottawa's seven-game winning streak.
Dan Boyle, Mats Zuccarello and Tanner Glass also scored for the Rangers (47-19-7), who now have 101 points and have clinched a playoff berth, while Cam Talbot made 23 saves.
"We played pretty well away from the puck and we were able to take it home and get two points to clinch a playoff spot," said Rangers coach Alain Vigneault.
"Probably caught their goalie on an off night and we were able to capitalize early."
Curtis Lazar had the lone goal for the Senators (37-25-11) as they failed to collect at least one point for just the second time in their past 18 games.
"They played better than we did from the start and we couldn't really pick it up," said Senators captain Erik Karlsson.
"We didn't find a way to fight through their tight neutral zone and we didn't really create anything to give us a chance to win."
New York's fifth goal knocked Hammond out of the game at 16:02 of the second period.
He was replaced by Chris Driedger, who was making his NHL debut. Driedger finished with 10 saves.
"I was just trying to not think about any pressure and just focus on trying to stop the puck," Driedger said of his debut. "I think I kind of blacked out on the first couple shots."
The Rangers took a 3-1 lead into the second period on two goals from Kreider and one from Boyle.
Kreider opened the scoring at 12:38, but the Senators tied the game just 19 seconds later when Lazar gained control of a bouncing puck in the Rangers end and beat Talbot with a quick shot from the face-off circle.
Boyle gave the Rangers the lead at 16:40 and with one minute left in the period Kreider got his second goal off a Stepan rebound that bounced straight up after Hammond made the initial save.
"You have to be able to handle momentum swings and to be able to answer with a goal is a big," said Kreider.
"I thought it was pretty sloppy for the first 10 minutes or so and then I think both teams did a good job executing the second half of that first period."
At 1:42 of the second period Zuccarello scored on a one-timer for a 4-1 lead before Glass essentially put the Senators to rest as he scored just five seconds after emerging from the penalty box. It was the first goal of the year for Glass.
"It's one of many hopefully," Glass said.
The Senators did have a five-on-three advantage for 34 seconds but didn't register a shot. They had just one shot over the final 86 seconds of the Glass minor.
Ottawa finished 0 for 6 on the power play with just five shots. The Rangers, who didn't get a power play opportunity, produced three shots while shorthanded.
Notes: Jared Cowen, Milan Michalek, Matt Puempel and Craig Anderson were scratches for the Senators. Kevin Klein and Martin St. Louis were scratches for the Rangers.