For the first time in Phillies history, a fan running on the field at Citizens Bank Park was subdued by a Philadelphia police officer using his Taser gun.

With 44,817 fans watching in the stands Monday night, the teenage male, wearing a black baseball cap, red T-shirt, and khaki shorts, ran on to the field during the eighth inning against the St. Louis Cardinals.

"This is the first time that a Taser gun has been used by Philadelphia police to apprehend a field jumper," Phillies spokeswoman Bonnie Clark said in a statement. "The Police Department is investigating this matter and the Phillies are discussing with them whether in future situations this is an appropriate use of force under these circumstances. That decision will be made public."

The fan made several loops in center field with security personnel and the police officer in pursuit. The officer appeared to fire several times before hitting the man. The man fell to the ground. He was then helped off the field.

The police officer "utilized his Taser" when a fan ran onto the field, said police spokesman Lt. Frank Vanore.

Running on the field during a game is a crime and has been for decades. Normally, such suspects are wrestled to the ground, escorted off the field, and arrested.

It was unclear Monday night if a Taser had ever been used on a Major League Baseball field to subdue such a suspect.

Vanore said the Police Department's internal affairs unit would open an investigation to determine if the firing "was proper use of the equipment."

Clark said the suspect was 17 years old and would be charged with criminal trespass. The team would not release his name because he was underage.

Police did not release the name of the man arrested or the charges.