CINCINNATI — 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 on 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 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," Cincinnati left tackle Andrew Whitworth said.
Cincinnati is just waiting to see how long it will be without Dalton, who had the NFL's top passer rating heading into the game. He is scheduled to see a specialist today to get a better idea of the treatment options.
"Mentally I'm fine," said Dalton, wearing a black cast. "It's unfortunate it happened at this point in the season. I'm doing all right. There are a lot of people who are way worse off than I am."
The Steelers rumbled with the Bengals during pregame warmups then led the whole way.
Steelers cornerback William Gay returned a McCarron pass 23 yards for a touchdown, and Ben Roethlisberger had another good day as Pittsburgh's resurgent offense kept rolling. Pittsburgh has 30 points in five straight games, a franchise record.
The game — and potentially Cincinnati's season — turned on one interception. Defensive end Stephon Truitt picked off Dalton's shovel pass in the first quarter, and Dalton got hurt while making the tackle.
McCarron threw a 66-yard touchdown to A.J. Green but also threw a floating sideline pass that Gay returned for a touchdown and a 23-7 lead early in the second half.
The dislike between the AFC North rivals bubbled out during warmups in a brief shouting-and-shoving match.
"We're going to defend ourselves aggressively," Steelers coach Mike Tomlin said. "Those confrontations occurred on our side of the ball after plays, outside of the ball, or outside of the 50 in pregame. Hey, that's our side of the 50."