The exchange began in the top of the fifth inning with the game tied at 1-1. Cardinals pitcher Carlos Martinez stepped to the plate after Lackey issued an intentional walk to Harrison Bader, putting two guys on base. Martinez quickly fell down 0-2 in the count on two cutters from Lackey. The Cubs veteran issued two pitches for balls before revving up for his fifth offering. He deposited the 82.5 mph cutter near the middle of the strike zone. Umpire Jordan Baker called the pitch a ball.
Lackey screamed at the umpire before Baker told him to stop. Martinez smacked the next pitch to center field, bringing in Kolten Wong and setting off the Cubs' battery. Lackey sprinted toward Baker like a man possessed. He also held a clinched fist. Contreras spiked his catchers mask - which hit Baker - and screamed at the umpire.
Both players were ejected.
The Cubs got out of the inning in the next at-bat and added seven runs in the next inning to take control of the contest.
"They got fired up after they saw everything that happened," Contreras told reporters in his postgame comments, according to MLB.com. "It happened because we care about the team, we care about the win, we care about the game. I know we are in a spot where we need to win most of the games to clinch the playoffs. Every game means a lot."
Lackey told the Chicago Tribune that he didn't regret his outburst.
"Not really, no,'' Lackey told reporters. "It was a pretty big spot right there and it cost me a big-league win and those don't grow on trees.''
"A big spot and huge game and he missed the pitch,'' Lackey said.
Lackey, 38, owns a 4.62 ERA this season. He is 11-11 in 28 appearances and has given up a National League high 34 home runs.
Chicago has now won four consecutive games heading into Game 3 of its four-game series against the Cardinals at 4:05 p.m. Saturday at Wrigley Field. The Cubs currently had a three game lead on the Milwaukee Brewers and four game lead on the Cardinals in the National League Central division.