Red Sox phenom Roman Anthony recorded his first MLB hit Tuesday night, and while Bostonians everywhere rejoiced ... all most of the internet could focus on was a fan in the stands who was cheering him on -- his sister.
Anthony -- the No. 1 overall prospect in baseball -- played in just his second-ever Big League tilt at Fenway Park ... and while he shined, it was Lia Anthony who found herself dominating the headlines.

Roman's sis was shown on the Sox vs.