"It was fun, man," Phelps said. "They put a lot of their regulars out there. I like that, because I can see how my stuff's playing against them. Those guys that have seen me before, I can see how my stuff is. That's as close to a real game as I've had this spring. It was a good atmosphere with the crowd. It was a good night."
Almost all of the damage against Phelps was done in the sixth, when the Red Sox rallied for four hits and two runs.
David Ross and Grady Sizemore started the rallies with singles, and then Dustin Pedroia clubbed a two-run double to right-center field.
Red Sox righty Clay Buchholz scattered five hits and three runs over five innings, walking one and striking out three.
Ichiro Suzuki went 1-for-4 with two RBIs for the Yankees. Francisco Cervelli drilled a solo shot over the Green Monster against Buchholz.
This was the second of two meetings this spring between the rivals.
They will meet for the first time in the regular season on April 11 at Yankee Stadium.
Up next: Left-hander CC Sabathia (1-1, 2.70 ERA) is scheduled to make his fourth start of the spring on Friday as the Yankees host the Pirates in a 7:05 p.m. ET game at George M. Steinbrenner Field in Tampa, Fla. Sabathia is looking to build on his previous outing, having thrown five no-hit innings against the Marlins in Panama. The Pirates counter with right-hander Edinson Volquez (0-2, 11.00), and the game can be seen on MLB.TV and MLB Network.