Rudolph Dunning, 25, died from stabs wounds suffered during a fight inside the Morris Avenue station in Soundview.
The victim, Rabia Bugum, 23, received stitches to her head and hand after the attack, which happened on a northbound No. 6 train at Brooke Avenue about 10:45 a.m. Wednesday, police said.
A man riding the No. 4 train in the Bronx slashed another rider’s face Saturday after an argument broke out between the two, authorities said.