CHICAGO (Dec. 18, 2005) -- Rex Grossman had waited a long time for this -- nearly 15 months -- so he was surprised and thrilled when the call finally came.

After replacing the struggling Kyle Orton in the third quarter, Grossman warmed the crowd and then the Chicago Bears ' offense in a 16-3 victory over the Atlanta Falcons at frigid Soldier Field.

"It was a thrill," Grossman said. "To finally be back and have crowd support like that is not really something you can explain unless you have the experience yourself.

"To run out in Soldier Field and have the whole crowd cheer you on after missing 26 games or whatever I missed and going through all the rehab and then to have that fan support running out in the huddle in a close game against the Falcons and playoff run -- it's a very unique situation. It's a memory I'll take with me the rest of my life."

Grossman added a different dimension.

The starter before breaking his left ankle in a preseason game in St. Louis, Grossman was 9 of 16 for 93 yards with an interception. It was plenty, though, with Chicago's staunch defense shutting down Michael Vick and the Falcons as the Bears rebounded from last week's 21-9 loss in Pittsburgh.

The NFL's No. 1 defense limited the Falcons to 231 yards. The Bears increased their lead in the NFC North to two games over Minnesota, an 18-3 loser to Pittsburgh. The teams meet Jan. 1 in the regular-season finale.

Chicago (10-4) turned to Grossman after watching Orton complete 2 of 10 passes for 12 yards in the first half.

Bears coach Lovie Smith praised Grossman but stopped short of naming him the starter for next week's game at Green Bay.

"I just felt like we needed a spark," Smith said. "Rex was ready to go. He had that look about him."

But when asked who would line up behind center next week, Smith said, "We'll go back and look at the tapes and decide who's starting."

But Atlanta defensive end Patrick Kearney said it should be an easy decision: "There is no doubt that he is a stronger quarterback and more of a threat to throw. It makes them a little more multidimensional than they were with Orton in there."

The moment he stepped onto the field, Grossman seemed comfortable -- despite the game-time temperature of 12 and a minus-3 wind chill.

In his first regular-season game since Sept. 26, 2004, when he tore the ACL in his right knee at Minnesota, Grossman got off to a quick start.

After the Falcons (8-6) punted on the opening drive of the second half, Grossman hit Muhsin Muhammad in stride over the middle for a 22-yard gain on the first play.

He hooked up with Justin Gage and Muhammad again as the Bears drove to the Falcons 8. But on third down, he threw an interception -- and the Bears got lucky.

Keion Carpenter picked off the pass near the goal line, then fumbled it. Gage recovered, and Thomas Jones ran it in from the 1 to make it 13-3.

Robbie Gould's third field goal, a 39-yarder, made it 16-3 with just under a minute left in the third period.

The Falcons were driving toward the end zone in the fourth quarter when Vick completed a pass to Michael Jenkins. Chicago's Mike Green delivered a hard hit, the ball popped up and Nathan Vasher intercepted it at the Bears 10.

The Falcons challenged, thinking Jenkins was down by contact. The interception stood and coach Jim Mora argued extensively, swiping his arm in the air, resulting in a 15-yard unsportsmanlike conduct penalty.

"I got no comment on the officiating," Mora said. "I think they do a wonderful job."

After allowing 190 yards rushing and 363 in all -- both season-highs -- the previous week, the Bears simply squeezed out the NFL's top running team. The Bears held an Atlanta team that was averaging 173.2 yards rushing to 114. And they sent the Falcons' playoff hopes plummeting.

After leaving last Monday's victory over New Orleans with bruised ribs, Vick ran for just 35 yards and completed 13 of 32 passes for 122 yards. He threw two interceptions.

Warrick Dunn carried 17 times for 81 yards.

For Chicago, Jones ran for 91 yards and a touchdown. Brian Urlacher had 11 solo tackles, 12 in all, and batted a pass. Vasher and Green each had an interception, and Adewale Ogunleye and Tank Johnson had a sack apiece.

But the story was Grossman's return. Smith had said Orton would remain behind center, barring injury. But he saw enough in the first half to change his mind.

"It's been a long road to get to this point, getting hurt again after getting hurt last year," Grossman said. "Sitting out the first 13 games and coming in the second half of this one. It feels amazing to get back out there and have some success, to be out there with my teammates and the stadium. It's been a blast. I had a great day."

Notes: Ogunleye became the first Chicago defensive end to reach 10 sacks since Richard Dent had 12 1/2 in 1993. ... The Bears had five starters -- safeties Mike Brown and Chris Harris, offensive lineman Terrence Metcalf, linebacker Hunter Hillenmeyer and fullback Bryan Johnson -- on the inactive list.