WGN just called the race for Rauner. Looking at some of the websites tracking votes it looks like Rauner won every county except Cook and he got over 30% in Cook which was probably key.
http://www.politico.com/2014-election/re...FmnMohOKrU
http://www.politico.com/2014-election/re...FmnMohOKrU
http://www.politico.com/2014-election/re...FmnMohOKrU