Andrew Shaw scored twice and Marian Hossa had a goal and two assists for the Blackhawks, who trailed 4-2 with 8:46 left in the second period. It was Hossa's 100th goal with Chicago and No. 439 for his career.
The Senators scored three times in a span of four shots in the second, but were unable to hold off the suddenly high-scoring Blackhawks. Kyle Turris and Milan Michalek each had a goal and an assist in Ottawa's fourth loss in five games.