A woman was pummeled on the subway after she refused the advances of another woman who was a total stranger, cops said.

The 68-year-old victim was riding an uptown 6 train when the suspect got on at the 59th Street/Lexington Avenue station at around 8 p.m. Wednesday and kissed her on the forehead.

When the victim resisted, the attacker grabbed her and punched her in the face and head, according to police.

The suspect, described as in her mid-40s, fled.