A man was stabbed on a packed PATH train Tuesday evening, Port Authority police said.

The attacker pulled out a knife during an argument with another rider and plunged it into the 38-year-old victim’s chest as the crowded southbound train was approaching the 23rd Street station just before 6 p.m., officials said.

The assailant then exited the train when it pulled into the station and ran off.

The victim was rushed to Bellevue Hospital in stable condition and was expected to survive.