Josh McCown has led the Chicago Bears to victory at Lambeau Field in his first start since 2011, grinding out a 27-20 win over the Green Bay Packers after they lost Aaron Rodgers to a suspected broken collarbone.

Green Bay's plans for the Bears were disrupted less than three minutes in as Rodgers fell heavily on his shoulder following a sack by Shea McClellin, with the quarterback ruled out of the match soon after.

Seneca Wallace came in to deputise with the Packers 3-0 ahead thanks to an early field goal, setting up an intriguing battle with his opposite number McCown as a pair of replacements attempted to prove their worth on the big stage.

Soon after Rodgers has left the field Chicago took full advantage to score the first touchdown of the night, as McCown found Brandon Marshall under pressure with a fine pick into the endzone from 23 yards.

The Bears then forced Wallace to give up an interception but then had a punt charged down in a frenetic first quarter, leading to Green Bay responding in style as James Starks broke clear to score on a 32-yard burst.

Chicago recovered as McCown led the visitors towards goal with a sustained drive, finished off smartly as Matt Forte found space to restore their lead from close range.

Green Bay turned to running back Eddie Lacy for a response, but were left with a one-dimensional attack that allowed Chicago to head into the locker room with a seven-point lead.

Lacy showed persistence and soon had the Packers level with a powerful burst into the endzone in the third quarter, before an onside kick caught the Bears cold from the restart.

Mason Crosby kicked the Packers ahead from that drive but Green Bay were unable to close out the match, as Chicago rallied to build a composed attack towards first and goal.

McCown then combined with Alshon Jeffrey three minutes from time to give Chicago the lead late on, using his height to collect a neat pass and a third touchdown of the night for the visitors.

The Bears then killed the clock as a Robbie Gould field goal restored their seven-point lead, with Green Bay unable to respond in the last 50 seconds as were beaten by Chicago on home turf for the first time since 2007.