In the top of the seventh, Pirates reliever Tony Watson plunked Arrieta in the left hip, causing benches to clear.
Watson was not ejected, but teammate Sean Rodriguez was, after appearing to throw a punch at David Ross of the Cubs.
Following the skirmish, Arrieta stole second base. He became just the fifth pitcher to steal a base in a playoff game since 1908.
The Pirates trailed 4–0 at the time of the incident.
After the brawl, Rodriguez took his frustration out on an unsuspecting water cooler.
- Kenny Ducey