Ben Roethlisberger guided the Steelers 52 yards in seven plays - abetted by Chicago's 12th penalty of the night - to set up Chris Boswell's 40-yard field goal with 26 seconds left, and Pittsburgh won its fourth straight after a 1-3 start as they slipped past the Bears 29-27 on Monday night.

A 10-point fourth-quarter lead turned into a one-point deficit following a fumble by punt returner Ray-Ray McCloud and a flash of brilliance by Bears rookie quarterback Justin Fields, who put Chicago in front with a 16-yard strike to Darnell Mooney with 1:46 to go.

Roethlisberger completed 21 of 30 passes for 205 yards and the two scores to Freiermuth while pulling off the 50th game-winning drive and 38th fourth-quarter comeback of his 18-year career. Rookie running back Najee Harris found the end zone for the fifth straight game and Boswell made three field goals - including two from over 50 yards - into the open end at perpetually windy Heinz Field.

Chicago appeared to get a stop on Pittsburgh's ensuing possession only to have linebacker Cassius Marsh - who spent training camp with the Steelers - get flagged for taunting after sacking Roethlisberger on third down.

Marsh's celebration looked relatively innocuous, though the league has cracked down on any semblance of taunting this season.

The call extended Pittsburgh's drive and allowed the Steelers to take a 26-20 lead with 2:52 remaining.

It took Fields all of 66 seconds to put the Bears in front. He took Chicago 75 yards in seven plays, and his strike to Mooney appeared to have the Bears in position to pull off a stunner before Roethlisberger and Boswell came through.

Chicago did get the ball to midfield in the final seconds, but Cairo Santos' 65-yard attempt into the closed end of the stadium was well short. Bears coach Matt Nagy praised Fields' resilience on a night he passed for 291 yards with a touchdown and an interception and ran for 45 more, but it wasn't enough.

Chicago's dozen penalties ran the gamut, from a pass-interference call that set up a Pittsburgh field goal to an illegal block in the second quarter that negated a 1-yard touchdown pass from Fields to Jimmy Graham. The Steelers, by comparison, were flagged six times for 30 yards.

Steelers linebacker T.J. Watt sacked Fields three times to push his season total to 11 1/2. Watt signed a contract in September that made him one of the highest-paid defenders in the league.

The Bears are off next week, then welcome Baltimore to Soldier Field on Nov. 21.