St. Louis had runners at second and third with one out when Pete Kozma hit a grounder to third baseman Luis Valbuena, who threw to first. Kozma was safe, and first baseman Anthony Rizzo threw home, but his throw sailed over catcher Welington Castillo.
Yadier Molina, the runner at third, broke for home. Castillo recovered the ball and threw to pitcher Travis Wood, who was covering at home, and the throw appeared to be in time, but home-plate umpire D.J. Reyburn ruled Molina safe.
"He looked out to me," Sveum said after the game.
Sveum immediately sprinted from the dugout to argue the call, and after some animated discussion, he was tossed. Third-base umpire Fieldin Culbreth escorted Sveum back to the dugout.
"It's a big play in the game at that time," Sveum said. "One of your best pitchers on the mound, if not our best pitcher, blocks the plate and gets there, and it's just an out call."
Said Wood: "My take was that he was out, but [Reyburn] has got the overall say, and he called [Molina] safe, and we have to overcome that and get after the next batter and make the pitches."
Molina appeared to kick Wood after the play, but the Cubs pitcher said the two became tangled up.
"I was trying to get out of there and just kind of stumbled," Wood said.
"I was trying to be aggressive, and we got the call our way," he said. "Any time you got an opportunity to be aggressive, you take it."
Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings, and you can follow her on Twitter @CarrieMuskat. This story was not subject to the approval of Major League Baseball or its clubs.