Mets' Pete Alonso Thrown To Ground In Wild Brawl With St. Louis Cardinals

Chaotic scene during the Mets vs. Cardinals game in St. Louis on Wednesday ... a wild brawl broke out during the middle of the game -- and NY superstar Pete Alonso was thrown to the ground by a Cards pitcher and coach.

The crazy moment went down in the bottom of the 8th inning at Busch Stadium ... after St. Louis third baseman Nolan Arenado was pissed following a pitch that nearly beaned him.

Arenado turned his body to avoid being hit by the Yoan López heater ... then nodded and motioned to Lopez as if to say "come get some."

The catcher and umpire tried to restore peace, but it was too late -- because both benches cleared in order to restrain Arenado from going after Lopez.

The two teams collided near home plate ... and, at one point, Alonso was dragged to the ground by Cardinals pitcher Génesis Cabrera and coach Stubby Clapp.

Thankfully, the melee was quickly broken up ... and Alonso and no one else was injured in the fracas.

But, afterward, Pete was pissed ... and told reporters that if he really wanted to, he could have "put someone in the hospital."

"I easily could," the Mets first baseman said, "but I was just out there trying to protect my guys."

Of course, the bad blood had been boiling between the two teams for a while ... especially after Tuesday night's game, when Alonso got drilled in the helmet by pitcher Kodi Whitley.

In fact, beanball drama happened earlier in Wednesday's game, when J.D. Davis was hit in the foot by a pitch from Cabrera in the top of the eighth inning.