The Senators allowed three third-period goals in the loss to the Blues

Jordan Cuero and Oscar Sundqvist also scored, and Jordan Binnington made 25 saves for St. Louis, which won for the third time in its last 10 games.

David Perron, Fabian Zetterlund and Shane Pinto scored, and Leevi Merilainen scored 27 for Ottawa, which is 3-2 over the first five games of a seven-game road trip.

Kessel swooped in a rebound for his second goal of the season to take a 4-3 lead just 1 minute, 48 seconds after Perrone scored his third goal of the season 7:31 into the third period to tie the game at 3-all.

Buchnevich once fed a feed from Braden Sheen for his third goal of the season 5:33 into the third period to give St. Louis a 3-2 lead. Buchnevich’s first power-play goal of the season snapped a 16-game scoring drought since his last goal on Oct. 25 in Detroit.

Cuero scored his team-leading seventh goal 2:01 into the third period to tie the game at 2-2 on a back-to-back pass from Jake Neighbors.

Zetterlund scored his ninth goal of the season with 1:33 left in the second period to put Ottawa ahead 2-1.

Senators captain Brady Tkachuk assisted on Zuterland’s goal in his return to the lineup after missing 20 games with a thumb injury that required surgery to repair torn ligaments.

Pinto scored his team-leading 12th goal of the season 10:11 into the second period to tie the game at 1-all.

Sundqvist scored his first goal of the season 7:59 into the second period.

Senator: Sunday night in Dallas.

Blues: Host Utah Saturday night.