Masar's two goals were her first in WPS.
"She has been practicing really well, and I noticed that she was creating a lot of chances," Red Stars coach Omid Namazi said in a release. "I felt it was a good time to give her a start and see how it works, and it worked to perfection. She got behind the Boston defenders and she finished tonight."
The Red Stars are now 3-5-3, and the win was the first for Namazi,.
Next up for the Red Stars is a 4 p.m. match on Sunday, July 4, against the Washington Freedom in Boyds, Md. to end a four-game road trip.
On Friday, the Red Stars got on the scoreboard first in the 13th minute. Defender Kate Markgraf started the attack with a long ball from the back to Red Stars forward Cristiane, who flicked a header to Masar, who made a run behind the Breakers defense.
"The timing was perfect," Namazi said. "That's how you draw it on the board."