Buddy Robinson and Andres Athanasiou scored 26 seconds apart in the third period and the lowly Chicago Blackhawks dealt the Penguins' playoff chances a significant blow in a 5-2 win on Tuesday night.
Pittsburgh began the night needing wins in its last two games over Chicago and Columbus to extend the longest active playoff streak in major North American professional sports to 17 years.
Instead, Petr Mrazek made 38 saves, Robinson scored just the fourth goal of his nomadic career to give Chicago a late lead and Pittsburgh finds itself on the outside of the playoffs looking in with just one game to go.
The Florida Panthers clinched one of the two wild-card spots in the Eastern Conference following losses by Buffalo and Pittsburgh. The New York Islanders can eliminate the Penguins with a win or an overtime loss against Montreal on Wednesday.
The Blackhawks, who are hoping to land the No. 1 pick in the draft and the chance to select Connor Bedard, responded by scoring four times in the last 10 minutes.
Robinson corralled a bouncing puck in the slot and knuckled it by Tristan Jarry to put Chicago up 2-1 with 9:38 remaining. Athanasiou found himself behind the Pittsburgh net moments later and flicked a shot at Jarry that somehow bounced off the goaltender and eventually made its way across the goal line.
Connor Murphy, Tyler Johnson and MacKenzie Entwistle also scored for Chicago.
The Blackhawks finish up their third straight losing season on Thursday against Philadephia.