In the second four-game series between two rivals of more than a century in as many weeks, it did not take long for tempers to flare in the blistering St. Louis heat.
After two quick outs from St. Louis Cardinals starter Miles Mikolas, Chicago Cubs outfielder Ian Happ stepped to the plate and the climate of the game quickly changed.
Following through on a 2-0 swing, Happ inadvertently struck Cardinals catcher and longtime former teammate Willson Contreras in the head, immediately drawing blood and eventually causing him to leave the game.
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Happ and Contreras hugged it out before the former Cub returned to the home clubhouse, yet that show of brotherhood between the two former teammates did not mean a thing to Mikolas.
After throwing inside to Happ on the very next pitch and not connecting, Mikolas intentionally threw far inside again on Happ, hitting him on the backside.
Despite no warnings issued, Mikolas was ejected after a brief meeting from the umpires, who likely determined both of the previous pitches to be retaliatory.
Mikolas emphatically argued the ejection, and was seen gesturing towards his hip, seeming to imply that he didn't hit Happ in a dangerous spot.
While the Cardinals' broadcast booth was in shock, fans around the baseball world were not impressed with Mikolas' antics:
Mikolas also appeared to taunt the Cubs' dugout, which drew the amusement of fans:
Additionally, the reaction of the Cardinals' broadcast crew received criticism from fans for seemingly endorsing hitting Happ with a pitch as retaliation:
The Cardinals' play-by-play announcer, Chip Caray, previously called games on TV for the Cubs from 1998-2004.
The Cubs and the Cardinals will continue their series Friday night, with the North Siders aiming to extend their season-high winning streak to seven.