A subway conductor was punched in the face by a passenger who was angry about being told to stop holding the subway doors open, police say.

The incident happened around midnight this morning, at the 125th Street-Lexington Avenue station in Harlem. An NYPD spokesperson said a 30-year-old man was holding the doors open on a southbound 4 train, and the conductor told him to stop, prompting the rider to go over to the conductor's window and allegedly punch him.

The conductor, who suffered bruising to the nose, then punched the rider back, giving him a bloody lip. Police identified the rider as Bronx resident Julio Leonardo, and say he was charged with felony assault.

"Riders don't fully understand how difficult and dangerous working in the subway can be," Transport Workers Union Local 100 President Tony Utano said. "This terrible incident is an ugly example. This was a disgusting and outrageous attack, and we will do everything we can to see that this criminal gets the punishment he deserves in court."

The union added that the conductor has a fractured nose. NYC Transit President Andy Byford said, "Our conductor was just doing his job, helping our customers and helping to keep the train moving when he was senselessly attacked. I am disgusted by this attack on my colleague and we are working closely with police to ensure that the perpetrator is held accountable."

It was the second violent incident at the station in the past 24 hours: On Thursday afternoon, a 34-year-old man was slashed after he said he accidentally bumped a male passenger on a northbound train. The victim told police he and another passenger got into a verbal argument which escalated when, according to the NYPD, the other passenger took out a knife and slashed him in the face.

The suspect fled and the victim, who suffered a laceration under his left ear, was taken to St. Luke's Hospital. The victim, John Kramer, later told WABC 7, "We bumped into each other and he grunted at me. He lunged at me with the knife in his hand. He stabbed me in my forehead, stabbed me in my ear."

No arrests have been made and the investigation is ongoing.