Browns star running back Nick Chubb finished with 106 yards on 18 carries for a 5.9 average. Dustin Hopkins kicked three field goals of 42, 34 and 43 yards.
Watson completed 16 of 29 passes for 154 yards, including a 2-yard pass to Harrison Bryant, followed by Watson's two-point conversion run, for a 24-3 lead with 9:11 left in the fourth quarter. He also rushed five times for 45 yards, including a 13-yard score.
It was the sixth straight win for the Browns over the Bengals in Cleveland. Quarterback Joe Burrow, fresh from signing his league-record five-year, $275 million extension on Saturday, finished just 14 of 31 for 82 yards.
Cleveland had 350 yards of total offense, to 142 for Cincinnati, including a 206-75 advantage rushing the ball. The Browns had more first downs, 21-4, and dominated time of possession, 35:50 to 24:10.
Cleveland had the best scoring chance in the opening 15 minutes, but Jerome Ford fumbled the ball on the exchange with Watson, then regathered the ball before getting stripped by linebacker Logan Wilson and safety Nick Scott. In his first game back from his ACL tear on the same field last Halloween, Bengals cornerback Chidobe Awuzie recovered the ball at the Cincinnati 13.
The Browns lost their starting right tackle Jack Conklin to a right knee injury midway through the second quarter. He was carted off the field and ruled out minutes later.
While the Bengals punted on all seven possessions of the first half, the Browns couldn't generate much more, before putting together a nine-play, 67-yard drive, capped off by Watson's 13-yard scramble for a touchdown.
A frustrating series for the Bengals came when they had fourth-and-1 at the Browns 40. Instead of going for it, Cincinnati took a delay-of-game penalty and punted from the 45. Brad Robbins' punt landed in the end zone for a net of just 25 yards.
Burrow looked like a quarterback who hadn't taken a preseason snap and was out six weeks with a right calf strain. Burrow was 6 of 14 for 36 yards in the first half.
Burrow's longest pass in the first half was for 12 yards to Ja'Marr Chase, accounting for Cincinnati's only third-down conversion in eight chances.
Down 10-0, the Bengals' defense forced a three-and-out to start the second half and then got the ball at the Cleveland 46. The Bengals drove to the Cleveland 24 before settling for Evan McPherson's 42-yard field goal and their first points of 2023.
Dax Hill intercepted a Watson pass with under 10 minutes left in the third quarter to give the Bengals possession at midfield. But the offense stalled and McPherson missed wide left from 51 yards and the Browns maintained their 10-3 lead.
—Field Level Media