The World Series hasn't just been a slugfest on the field ... Houston Astros manager A.J. Hinch was involved in a heated altercation after Game 1 and cops were called ... TMZ Sports has learned.

Here's what we know ... Hinch was hanging out at the bar at the team hotel in Pasadena on Tuesday night after Houston lost Game 1 to the Dodgers.

We're told he was having some drinks -- when some hotel guests came in and started talking trash about the Astros.

Sources say Hinch "snapped" and unleashed on the other patrons -- cursing and yelling in the middle of the bar. One witness tells us the incident turned physical and cops were called to separate the two parties.