PITTSBURGH — T.J. Watt scooped up a fumble by DeShaun Watson and ran 17 yards for the go-ahead touchdown midway through the fourth quarter, and the Pittsburgh Steelers beat the Cleveland Browns 26-22 on Monday night in a game overshadowed by a serious knee injury to Cleveland star running back Nick Chubb.

The Steelers (1-1) beat the Browns (1-1) for the 20th straight time at home in the regular season when outside linebacker Alex Highsmith — who returned an interception for a touchdown on the game’s first snap — beat Cleveland left tackle Jedrick Wills Jr. off the edge and chopped the ball out of Watson’s hands.

Watt picked it up and raced home as Pittsburgh extended its home winning streak on Monday night to 21 straight dating to 1991.

Cleveland allowed an opponent to score two defensive touchdowns for the first time since Pittsburgh did it on Oct. 16, 1983.

The Browns played most of the final three quarters without Chubb, who took a handoff from Watson early in the second quarter and reached the Pittsburgh 3.

Steelers safety Minkah Fitzpatrick dove at Chubb’s legs, and the four-time Pro Bowler’s left leg bent awkwardly underneath him.

He was carted off the field.

Jerome Ford, Chubb’s replacement, ran for 106 yards and caught a 3-yard touchdown pass for the Browns, but Cleveland’s miscues cost it a chance to win at Pittsburgh in the regular season for the first time since 2003.

Watson completed 22 of 40 for 235 yards with a touchdown and an interception.

He was also flagged twice for unsportsmanlike conduct for grabbing the facemask of a Steeler while running.

The penalties cut a pair of promising drives short.

Kenny Pickett and the Steelers’ offense struggled. Pickett went 15 of 30 for 222 yards.