Petr Mrazek made 32 saves for the Blackhawks (21-47-5), who had won two in a row.
“We just didn’t match their intensity,” Chicago coach Luke Richardson said. “I think they were a step ahead of us everywhere, and unfortunately, we paid the price. Petr kept us in and gave us a chance to get back in the game, but our power play that has been very good for us lately, tonight, was a little sloppy.
“Credit to Ottawa, they outskated us and outworked us and they were the team that played and traveled last night, and we just didn’t match that. I think we started to play a little bit in the second period and the third period, but we had a hard time getting on the inside. I just thought they had a little more determination than we did tonight.”
Blackhawks rookie forward Connor Bedard had two shots and was minus-2 in 19:55 of ice time in his first trip to Ottawa.
“We know what he’s trying to do," Forsberg said of the scouting report on Bedard. "He’s trying to come at defensemen and kind of toe drag the guy and shoot between the legs. I think [our defensemen] did a really good job at keeping the stick on him so he didn’t really get any really dangerous shots. They did a really good job.”
Giroux gave the Senators a 1-0 lead 36 seconds into the first period with a short-handed goal. He took a centering pass from Jacob Bernard-Docker on a 3-on-2 rush and beat Mrazek with a wrist shot from the slot.
“The first period was the difference. It’s as simple as that,” Chicago forward Nick Foligno said. “We’ve had trouble with our starts. I don’t know what it is. Obviously, they were excited coming back to a sold-out rink, and we just didn’t have the same energy and compete that we needed.”