Ehrhoff broke a 2-2 tie with a goal at 9:02 of the third and then assisted on an insurance goal by Cody Hodgson that closed out the scoring.
Dougie Hamilton had a goal and an assist for Boston, and Rich Peverley added the only goal of the second period. Anton Khudobin allowed four goals on 26 shots for the Bruins, who lost their second in a row.
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