CHICAGO | Desmond Clark heard the boos that spiraled toward Rex Grossman just a few weeks ago and didn’t get it.

Now, the quarterback who was hailed at the end of last season is earning praise again after a difficult preseason.

Grossman had his best game as a pro, and the Chicago Bears’ defense silenced Detroit’s Roy Williams and the Lions 34-7. Grossman set career highs Sunday with 289 yards and four touchdown passes.

“They’ve been on him so hard the last few weeks,” said Clark, who caught five passes for 85 yards and a touchdown. “You sit back and you’re like, ‘Damn, just a few months he was (hailed) and now you’re booing him.’ I like what he’s doing. I hope he can keep it up.”

Plagued by injuries since being drafted in the first round in 2003, Grossman is healthy and producing. He completed 20 of 27 passes with no interceptions and set a career-high in yards for the second straight week after throwing for 262 in a 26-0 season-opening win at Green Bay.

John Gilmore caught two short touchdown passes, including a 3-yarder just under five minutes into the game. Bernard Berrian had five receptions for 89 yards, with a lunging 41-yard touchdown catch in the second quarter.

“We’ve always known we had a good offense,” Grossman said. “It’s just a matter of executing when there are plays to be made. In the first couple of games we definitely have.”

A defense that handed the Packers’ Brett Favre the first shutout of his career held the Lions to 245 yards and recovered three fumbles. Detroit (0-2) committed 14 penalties for 104 yards, seven for 58 yards in the first quarter alone. And a hands-to-the-face call against Jamar Fletcher in the third quarter wiped out an interception that Boss Bailey returned about 25 yards to the end zone.

Williams caught six passes for 71 yards after guaranteeing a win over the Bears. He was booed loudly after catching his first pass.

Jon Kitna wound up 23-of-30 for 230 yards and was sacked six times.

Williams said Bears linebacker Brian Urlacher brought up the guarantee.

“He just said, ‘You’re going to guarantee next week as well?’ and I said, ‘Yeah, sure will. As long as we do what we’re supposed to do.’ They did nothing special. They’re a good defense, they run to the football, they get pressure on the quarterback.”

Bears defensive tackle Tommie Harris dismissed Williams’ guarantee, saying, “A lot of talk comes from a lack of confidence in what you can do. … My rookie year here (2004), we used to talk a lot and we weren’t that good.”

They talked quite a bit before their playoff game against Carolina last year and lost.

Chicago (2-0) wasted no time pouncing on Detroit.

The Lions’ first possession ended on the third play when Tank Johnson sacked Kitna and jarred the ball loose. Urlacher recovered at the Detroit 3, and Grossman connected with Gilmore for a touchdown.

Detroit’s second possession started with a 29-yard run by Kevin Jones that put the ball on the Bears 41, but Alex Brown stripped him on the next play and recovered the fumble. That led to a 32-yard field goal by Robbie Gould.

The lead grew to 17-0 in the opening minute of the second quarter when Grossman found a lunging Berrian at the goal line. Berrian juggled the ball and tucked it in as he hit the ground, but the Lions did not challenge it.

The Associated Press