The Rangers, with little left in their tank last night, made one last push in the hope of continuing their winning streak. The puck came to the blade of Derek Stepan with just over 13 minutes remaining in a 2-2 game, wide open in front of the Senators’ net with a world of opportunity awaiting. “He scores that,” said coach John Tortorella after the Rangers lost, 3-2, to the Senators at the Garden last night, “you never know where it goes.” Instead of finding the back of the net, the puck found the butt end of Robin Lehner’s stick, the Senators’ goalie sending the puck up into the netting and the momentum back with his team. With the ice tilted, Jakob Silfverberg got the game winner with 4:41 remaining, lifting a rebound over Henrik Lundqvist’s right shoulder. “It’s a goal scored with four and half minutes left,” said Lundqvist, who was terrific in making 36 saves. “Of course you’re going to be upset.”