As of this writing (1:31 AM Illinois time), Bill Brady has just a 546-vote lead on Kirk Dillard in the Illinois Republican gubernatorial primary.
And things are liable to get closer before the end of the night. How so? Because essentially all of the outstanding vote is in Cook County (Chicago), where Dillard is picking up 18 percent of the vote so far and Brady just 5 percent. If I project out the remaining Cook County precincts based on the previous ones, I show Dillard picking up another 800 votes and Brady another 225. That would make the statewide margin Dillard 154,876, and Brady 154,877 -- an advantage of literally one vote for Brady.
EDIT: In the Democratic gubernatorial primary, incumbent Pat Quinn is performing slightly better than his statewide numbers in Cook County and it looks like his ~7,000-vote advantage over Dan Hynes will expand rather than contract. There might be a recount but unless there are mass irregularities or whole stashes of ballots that haven't been counted yet, it is unlikely to change the outcome.