Grossman replaced an injured Brian Griese and threw a 59-yard pass to Bernard Berrian for the go-ahead score with 3:11 remaining, leading the Bears to a 17-6 victory over the Oakland Raiders on Sunday.
"It was unbelievable, something you can't describe to someone who hasn't been in that position," Grossman said. "It's a great feeling to come in and be able to pull one out."
Sebastian Janikowski's 52-yard field goal with 4:04 remaining gave Oakland (2-7) a 6-3 lead that looked as if it could be enough on a day when neither offense could move the ball.
Then Grossman, who had struggled in his first game since Sept. 23, turned back into Good Rex, the quarterback who helped lead the Bears (4-5) to the Super Bowl last season instead of the one whose turnovers cost him his job earlier this season.
After the Bears almost botched the kickoff, Grossman hit Cedric Benson on an 11-yard pass over the middle.
On the next play, Berrian sprinted past Chris Carr, caught the deep pass in stride and went into the end zone with the go-ahead score.
"We were trying to get the right matchup all game, and we couldn't get it, and then it happened," Berrian said. "At that time of the game, we needed anything to happen, a long run or a long play."
The Bears took advantage of man coverage by a backup cornerback forced into a starting role because of injuries to Nnamdi Asomugha and Fabian Washington. Carr was solid for almost the entire game, with six tackles and one pass breakup, but got beat on the one play that mattered most.
"They did a very good job of selling me on the go route," Carr said. "He gave me a little hesitation and I wasn't running as fast as I should have been running. He got a step on me. Once he got a step on me, he got me."
Grossman, who had been 5-for-12 for 72 yards before the winning drive, leaped into teammate John Tait's arms and flashed a smile that hadn't been seen in a long while.
Grossman was benched after throwing six interceptions and only one touchdown pass in Chicago's first three games. Combined with his 23 interceptions in 19 games last season, the Bears had grown tired of all of Grossman's mistakes and decided to go with the veteran Griese.
The move back to Grossman didn't look like it would pay off when he fumbled the first center exchange with Olin Kreutz. He did little positive other than the one big pass to Berrian, finishing 7-for-14 for 142 yards. But most importantly, he had no turnovers.
"I hope people appreciate that Rex hasn't shut it down," Kreutz said. "He hasn't moped around our building. He's kept himself prepared and ready to play. I hope it shows a lot of people what everybody on this team already knew about Rex. He's still a professional, and he's still going to be ready to win."
The Bears won in their first game after the bye, but still have plenty more to do if they want to make it back to the playoffs. It just might be Grossman who has to take them there. Griese's shoulder injury is not believed to be serious, but coach Lovie Smith said he wanted to savor this win before making any decisions about the quarterback next week.
The Raiders went three-and-out on their next drive after Grossman's TD pass.
After a Chicago punt, Adewale Ogunleye then forced a fumble by Josh McCown that Israel Idonije recovered at the 3 with 1:39 remaining. Benson ran it in on the next play to seal the victory. Benson finished with 76 yards on 29 carries.
McCown was booed during pregame introductions by the fans eager for top pick JaMarcus Russell to play. McCown didn't silence the critics, going 1-for-13 in a stretch that began late in the first half and ended after Benson's touchdown put the game away.
"Obviously the kid's here for a reason and they picked him No. 1 for a reason," McCown said. "At some point, he's going to have to play. Obviously for us we hope that's not this year because we want to get on a roll here and start winning some ballgames."
Justin Fargas ran for 81 yards on 23 carries in his second straight start, but also lost a key fumble in the second half. Oakland finished with a season-low 193 yards of offense and lost its fifth straight game.
Raiders coach Lane Kiffin backed up his bold talk during the week and did kick the ball to Chicago's dangerous returner Devin Hester almost every time. Despite getting more chances that usual to add to his nine return touchdowns in less than two seasons, Hester found little room to run against Oakland's coverage units.
He returned one kickoff from 8 yards deep in the end zone and only managed to make it out to the 11. He also twice lost 4 yards on punt returns. Hester's one big play, a 64-yard punt return, was wiped out by a holding call on Brendon Ayanbadejo.
"I did get frustrated a couple of times, but you just have to stay patient and know your opportunities are going to happen," Hester said.
Hester had 14 yards on six punt returns and 34 yards on two kickoff returns. ... Oakland RB LaMont Jordan was in sweatpants and didn't play as Kiffin wanted to give Dominc Rhodes a chance. Rhodes had only one carry for 2 yards.