– Andy Dalton's right thumb hurt a bit as he came to the sideline. He gripped a football to gauge how much he had hurt his passing hand while making a tackle.

One painful squeeze told him something was badly wrong.

Dalton broke his thumb while making a tackle after his interception Sunday, turning Cincinnati's season upside-down in an instant. With a chance to clinch the AFC North at home, the Bengals lost their quarterback and got blown out, too.

The Pittsburgh Steelers battered backup AJ McCarron while pulling away to a 33-20 victory that left the division and the top AFC playoff seed up for grabs.

"It's huge frustration," left tackle Andrew Whitworth said.

Cincinnati (10-3) is waiting to see how long it will be without Dalton, who had the NFL's top passer rating heading into the game. He will see a specialist on Monday to get a better idea of the treatment options.

"Mentally I'm fine," he said. "It's unfortunate it happened at this point in the season. I'm doing all right."

The Steelers (8-5) rumbled with the Bengals during pregame warmups and then led the whole way, sending Cincinnati to its first lopsided loss of the season.

William Gay returned one of McCarron's passes 23 yards for a touchdown, and Ben Roethlisberger had another good day as Pittsburgh's resurgent offense kept rolling. Pittsburgh has scored 30 points in five consecutive games, a franchise record.

The game — and potentially Cincinnati's season — turned on one interception. Stephon Truitt picked off Dalton's shovel pass in the first quarter, and Dalton got hurt while making the tackle.

Dalton has been one of the NFL's most durable quarterbacks, missing only half a game during his five seasons because of injury. Now, the Bengals' chances are in the hands of a second-year quarterback from Alabama who missed all of his rookie season because of a sore shoulder.

"If you don't [have confidence] you're doomed," said McCarron, who won two national titles with the Crimson Tide but had thrown only four passes in the NFL until Sunday.