"It just feels amazing to get back out there and have some success," Grossman said after completing 9-of-16 for 93 yards and leading two scoring drives.
A passing attack void of life started to look like the type of weapon that could take a team deep into the playoffs. Now, they just need to worry about keeping Grossman healthy after he missed most of the 2004 and 2005 seasons with injuries.
"I thought we needed a spark," Bears coach Lovie Smith said. "The defense was playing well. We were moving the ball fairly well on the offensive side.
"I just felt like we needed a spark and of course Rex was ready to go. He had that look about him. It was a gut feeling and we went with it."
Yet Smith wouldn't confirm Grossman will start against Green Bay.
"Rex played very well tonight. We're going to go back and look at the tape," he said.
When he got the word at halftime, Grossman couldn't say it was expected even after Orton struggled with no third down conversions in seven tries and 2-of-10 passing for 12 yards.
"It was just a complete surprise to me," Grossman said.
Grossman's first pass was a perfect 22-yard strike to Muhsin Muhammad at the Falcons' 29-yard line.
"That definitely gave me a lot of confidence," Grossman said. "Whatever jitters I did have settled me down right there. Moose ran a great route, I got great protection and they bit up on the play-action.
"There was a void over the middle and I just had to drop it in over the linebackers. It was one of those plays that made me breathe easier a little bit."
Besides being sharp for a quarterback who'd been out a season and a half with injuries, and hadn't even taken a first-team snap until prior to last week's game against Pittsburgh, Grossman also benefited from good fortune.
He had marched the Bears 43 yards to Atlanta's 8 and -- owning a 6-3 lead -- threw an interception to safety Keion Carpenter in the middle of the field. But Carpenter fumbled the ball without having it stripped and wide receiver Justin Gage fell on it at the Falcons' 1-yard line.
"I wish I could have had that interception back, but it turned out to be a 7 1/2-yard play," Grossman said.
"I was lucky. And I think I deserve a little luck," he added, referring to his injury problems.
One play later, Thomas Jones (93 yards, 27 carries) snuck into the end zone for a 1-yard touchdown to provide a comfortable 13-3 Bears lead. Grossman had completed 3-of-6 on the drive, which put the Bears inside the 10.
On his third possession, Grossman led a 50-yard drive with completions of 10 yards to Muhammad, 19 yards to Gage, 11 yards to fullback Jason McKie and 3 yards to Jones. It ended with Robbie Gould's fourth field goal of the game, a 38-yarder with 53 seconds left in the fourth quarter for a 16-3 Bears lead.
"It was good to see him get back out there and he gave us a lift," Smith said.
Grossman hadn't played in a regular-season NFL game since Sept. 26, 2004, when he went down with a torn right anterior cruciate ligament. His last appearance in a Bears uniform had been the Aug. 12 preseason game in St. Louis this year against the Rams. In that game he suffered a broken left ankle.
In the third quarter, Grossman threw for 83 yards on 7-of-12. The Bears had gone 0-for-7 on third down conversions in the first half and had converted only three of their previous 30 third downs. When Grossman entered the game, they converted 3-of-8 third-quarter third-down conversions and had the fumble recovery on a third down, as well.
With Orton still in the game, the Bears had seized a 6-3 halftime lead. However, he had little to do with building that lead.
"Today I just went out and didn't play well," Orton said. "I'm disappointed obviously. I'm not going to hide the fact."
Gould kicked a 35-yard field goal in the second quarter after the Falcons' Todd Peterson made a 30-yarder with 10:16 left in the first half for the game's first score. The tying score came with 6:33 left in the second quarter and ended a 52-yard drive, highlighted by Bernard Berrian's 37-yard run around left end on an end-around play.
"It was an outstanding game by him, also," Smith said of Berrian. "We needed a punt returner and I thought he did a great job with the punt returns. When we threw him the football he made plays. "Stretching the field -- we missed him a couple times -- but just having a guy like that stretching the field helped."
Berrian put the Bears in field position for their second score with a 24-yard punt return in his first game replacing Bobby Wade, who was cut last week. The Bears then benefited from a 25-yard pass interference penalty against DeAngelo Hall on Muhammad and Gould kicked a 29-yarder for the 6-3 lead with 2:03 left in the first half.
With the Bears protecting a lead, the defense took over. Mike Green and Nathan Vasher both had interceptions in the second half. Vasher's came on a ball which popped into the air at the 10-yard line, and Atlanta coach Jim Mora Jr. asked for a replay. The interception was not overruled and Mora Jr. earned a 15-yard unsportsmanlike conduct for complaining.
The review of the game tape and Grossman's appointment as starter Monday seem foregone conclusion at this point.
"I don't know what they're going to do," Grossman said. "I'm going to be ready when they call me."