Braun raced to first base after hitting a ground ball to shortstop in the third inning and hit the bag with his right foot just as Starlin Castro's off-balance throw hit Anthony Rizzo's glove. The call from first-base umpire Kerwin Danley was out, but Braun signaled immediately to the bench asking for a review, and manager Ron Roenicke obliged.
After two minutes and 20 seconds, the call was overturned. Braun was called safe. He moved to second on a single from Jonathan Lucroy that plated Carlos Gomez, but was stranded when Khris Davis grounded into a forceout to end the inning.
It was Roenicke's third challenge under the new system of expanded replay, and the second time he had a call overturned.
Cubs manager Rick Renteria then challenged a call in the eighth inning, which was overturned after a 1 minute and 5 second review.
Milwaukee's Jean Segura hit a grounder to second baseman Emilio Bonifacio, who threw to first. Danley called Segura safe, but after review, the call was overturned and Segura was out. The next batter, Rickie Weeks, singled, but Wesley Wright struck out Gomez and Scooter Gennett to end the inning.
The Cubs have now challenged 10 plays, and are 5-5.
Adam McCalvy is a reporter for MLB.com. Read his blog, Brew Beat, and follow him on Twitter at @AdamMcCalvy. 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.