Christensen, Dan Girardi and Michael Del Zotto all scored in the first period, putting the Rangers ahead 3-0, and New York hung on to improve to 3-1-1 on a six-game homestand.
Henrik Lundqvist stopped 25-of-28 shots, boosting his season's record to 4-3-3.
The game marked the return of Rangers "agitator" Sean Avery from the minor leagues. He played less than 5 minutes in his season debut.
Carey Price made 24 saves in the setback.
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