big leagues one full game into the era of expanded instant replay. so far it seems to be working. reporter: it didn t take long for the first challenge to an umpire s call. top of the fifth in pittsburgh. cubs hit into a double play. but chicago manager rick renteria challenged the ruling, believing his runner may have been safe at first. he wasn t and the ruling stood. the call on the play has been confirmed. reporter: then the first call to be overturned is as the braves/brewers came in milwaukee. it came after ryan braun was called safe at first. atlanta manager fredi gonzalez challenged and after a delay of just 58 seconds, braun was called out. i had a pretty good idea i was out. i think for all of us, we just hope they get it right. and they he did get it right. reporter: in pittsburgh in the top of the tenth, cubs runner on first and ruled safe. pirate s clint hurdle went out to discuss it and challenged the call. umps huddled. spoke to replay officials in new york who