A subway rider beat a man on an Upper East Side train with a cane after he accidentally bumped into him, police said.

The suspect, a man in his early 20s, was on a northbound No. 6 train at about 8:30 p.m. on Oct. 30 when a 59-year-old man bumped into him, cops said.

The suspect launched into a rage and hit the man in the face as the train approached the 96th Street Station, authorities said.

The 59-year-old got off the train and called cops after leaving the station.

The suspect has not been caught by police. He was last seen wearing blue jeans, a white hooded shirt and a white baseball hat, authorities said.