Bruins 4, Senators 2 .

OTTAWA - Brad Marchand scored twice and Nathan Horton had a goal and an assist to lead the Boston Bruins to a 4-2 win over the Ottawa Senators on Friday night.

Tuukka Rask made 32 saves and Dennis Seidenberg also scored for Boston, which acquired three-time all-star defenceman Tomas Kaberle from Toronto in one of two trades completed by GM Peter Chiarelli earlier in the day.

Kaberle made his Bruins debut along with former Senators centre Chris Kelly, who was acquired in a trade with Ottawa on Tuesday.

Marchand scored his second goal of the game, Boston's third goal of the third period, to put the Bruins up 4-1 at 15:52, just 32 seconds after Seidenberg's power-play goal.

Bobby Butler scored for a third straight game early in the second to give the Senators a brief 1-0 lead. Alex Kovalev scored a power-play goal with 1:30 left in the third to draw Ottawa within two.

Robin Lehner stopped 29 shots for Ottawa, which swapped goalies with Colorado on Friday.

Senators GM Bryan Murray acquired Craig Anderson from the Avalanche in return for Brian Elliott after trading left wing Jarkko Ruuttu to Anaheim on Thursday night.

Kaberle was acquired from Toronto earlier in the day in a trade that sent Boston prospect Joe Colborne and two draft picks to the Maple Leafs.

Kelly was traded by Ottawa to Boston on Tuesday night following the Senators' shootout loss to the New York Islanders.

The Bruins also cut a deal with Atlanta on Friday, acquiring centre Rich Peverley and defenceman Boris Valabik in return for right wing Blake Wheeler and defenceman Mark Stuart. Peverley will join the team Sunday in Boston, while Valabik will report to Providence of the AHL.

Marchand scored 6:47 into the second to tie it at 1-1, using Ottawa defenceman Andre Benoit as a screen to fire a wrist shot past Lehner into the top of the net.

Horton scored his 15th goal 9:47 into the third to make it 2-1. Seidenberg increased the lead to 3-1 with a power-play goal at 15:20.

Anderson arrived at Scotiabank Place after the game was underway. He got dressed after traveling from Denver and took Pascal Leclaire's place as the Senators' backup late in the first period.

NOTES: Kaberle wore No. 12. The Bruins have retired Hall of Fame centre Milt Schmidt's No. 15, which the Czech defenceman wore with Toronto. ... Kelly, who is wearing No. 23 for Boston, raised his stick to acknowledge a standing ovation when a video tribute ran on the scoreboard during a stoppage in play in the first. The No. 22 he wore with Ottawa belongs to RW Shawn Thornton ... Andre Benoit played his first NHL game. RW Francis Lessard, who was recalled along from Binghamton of the AHL along with Benoit, made his Senators debut ... Leclaire has missed 25 games in a row because of a lower-body injury. He had not been in uniform since Dec. 17, when he was injured in the warmup prior to a 6-5 overtime loss in Colorado.