Pittsburgh Bureau of Police officers providing security for the Pittsburgh Pirates game responded when a fan accessed the field at about 3:40 p.m.
It was the top of the sixth inning when a male casually walked onto the field towards home plate. He appeared to extend his hand toward the players for a handshake.
Officers quickly intervened, escorting the male off the field where he was arrested and handcuffed in front of the Philadelphia Phillies dugout.
The male told police he did it because a friend dared him to.
The 24-year-old, who is from Central Pennsylvania, faces charges of trespassing and disorderly conduct.
Tonight, the City-County Building is illuminated to recognize Poison Prevention Week and the 50th Anniversary of "Mr. Yuk" in partnership with Children's Hospital of Pittsburgh of UPMC.
For questions about the lighting at the City-County Building, please reach out to the Office of the Mayor.