Watson looked rusty and indecisive at times in his first full game since Sept. 24, when he sustained a strained rotator cuff in his throwing shoulder. He completed 19 of 30 passes for 219 yards — 139 to Amari Cooper.
But while Watson and the offense struggled to re-establish any rhythm following their time apart, the Browns (5-3) leaned on their top-ranked defense to stifle the Cardinals (1-8), who started rookie quarterback Clayton Tune.
Cleveland’s defense set up both Watson TD passes with turnovers, and the Browns recorded seven sacks, with Dalvin Tomlinson getting Tune 2 1/2 times.
Watson connected with Cooper on an 11-yard scoring pass in the second quarter and hooked up with tight end David Njoku on a 5-yarder in the third.
Kareem Hunt had a 3-yard TD run and Dustin Hopkins kicked two field goals for Cleveland.
Arizona has lost six straight.
The Cardinals announced Saturday that Tune, a fifth-round pick from Houston, would start instead of activating Kyler Murray, who is close to making his return after suffering a knee injury last season.
Earlier this week, Arizona traded Joshua Dobbs, their starter in the first eight games while awaiting Murray’s return.
Tune couldn’t get anything going against the Browns, who pressured him on virtually every snap. He completed 11 of 20 passes for 58 yards with two interceptions.
Already short-handed due to injuries, the Cardinals were also without running back Emari Demercado and receiver Michael Wilson, who were both inactive.
The Cardinals had just 31 yards at halftime as their six first-half possessions went punt, punt, punt, interception, punt and punt. It didn’t get much better after halftime.
The Browns led 13-0 at the break on the strength of two field goals by Hopkins and a fluky touchdown, which came after Denzel Ward picked off Tune.
Cleveland caught a huge beak on the scoring play as Watson’s throw deflected off the helmet of Cardinals defensive lineman Dante Stills, caromed high in the air and was grabbed by Cooper in the end zone.
A week ago, the Browns were victimized by a similar play when a late pass by backup QB P.J. Walker bounced off the helmet of a blitzing Seattle defender and was picked off, setting up the Seahawks’ comeback win.
Murray’s next chance to play is next week at home against Atlanta.
The Cardinals wanted to give Murray as much time as possible to get ready after months of rehab and inactivity. Once Murray is back on the roster and behind center, Arizona will have time to evaluate whether to stick with Murray, who signed a five-year, $230 million contract last season, as their franchise QB or go in another direction.
Cardinals: LB Zaven Collins was evaluated for concussion in the first half and returned. ... OLs Will Hernandez (knee) and D.J. Humphries (ankle) both went out in the second half. ... DL Roy Lopez was also treated for an injury that wasn’t announced.
Browns: Starting LT Jedrick Wills Jr. appeared to suffer a serious lower leg injury. He was carted off in the third quarter with his right leg immobilized. .... WR Marquise Goodwin left with a head injury early in the third quarter. He was assisted from the field and taken straight to the locker room for evaluation and treatment.
Browns at Ravens, 1 p.m., Fox, 1290, 95.7