Phillips gave the Senators a 2-1 lead 7:50 into the second and produced what turned out to be the game-winning goal with 6:25 to play in regulation.
The second goal by Phillips put Ottawa in front 4-2 and the Senators survived a score by Martin Erat with 10 seconds to play.
Jason Spezza had the other two Ottawa goals, one of them putting the Senators in front for good at 3-2 late in the middle period.
Phillips has been in the NHL for 14 seasons, all of them spent with Ottawa. The defenseman's goals Thursday were his first two of the season and gives him 62 for his career. He scored twice as many goals Thursday as he did during the entire 2010-11 season.