An irascible subway passenger who pushed a panhandler onto the tracks was arrested while coolly waiting for his train early Saturday by an off-duty parole officer who witnessed it, police said.

Joseph D'Agostino, 33, was rescued from the tracks by the parole officer, Nelson Nieves, and treated for minor injuries, said police Sgt. Tina Mohrmann.It was just the latest incident in which subway riders have fought back against perceived threats by other people.

Last week, a teenager aboard a subway train in the Bronx stabbed to death would-be thief David Richmond, 19, who had tried to steal his companion's gold chain. Richmond had previously been arrested in the subway system for fare evasion, assault and possession of a deadly weapon.

Also last week, another teen pulled out a revolver and started shooting at four other youths who tried to grab his gold chain. Two of the assailants were hit, and one, 17-year-old James Wortham, died.

The incidents were reminiscent of "Subway Gunman" Bernhard Goetz, who shot four youths aboard a subway train in 1984 because he thought they were about to rob him. Goetz, a hero to some, was acquitted of attempted murder but served time on a weapons charge.

Mohrmann said the latest incident unfolded about 1 a.m. in a Manhattan subway station when D'Agostino asked passenger Osvaldo Soli, 31, for money.

"The guy asked (Soli) for change, and the passenger was not pleased and pushed him onto the tracks," Mohrmann said. "Then (Soli) stood there waiting for his train. He's not too bright."

Nieves, an off-duty New York State parole officer, witnessed the attack, grabbed Soli and held him until the police arrived, Mohrmann said.

Charges against Soli were pending, authorities said.