"There were a lot of question marks," Cutler said. "How were we going to do on offense? Are the plays going to work? Are we going to be able to block them? Am I going to complete balls? So to go out there, it wasn't pretty, it wasn't perfect, we didn't think it was going to be. We made plays when we had to make plays."
Cutler threw for 242 yards behind a line with four new starters. Marshall had eight grabs for 104 yards, and the offense pulled it out after struggling most of the way.
The Bears made big changes in the offseason, parting with star linebacker Brian Urlacher and hiring Trestman to replace the fired Lovie Smith with the idea that he could spark the offense and lead them to the playoffs after missing out five of the past six years.
Clearly, there's work to do. The offense seemed stuck most of the afternoon but came through in the end, with Cutler completing 21 of 33 passes. He also had two touchdowns to go with an interception.
"I think it tested us and our backbone because it didn't go the way we wanted it to go, certainly, in the first half," said Trestman, who coached the CFL's Montreal Alouettes the past five seasons. "But the guys hung in there together, at halftime pulled themselves together and the team went out and played every play and were able to come out on top."
"They didn't stop us one time," Green said. "They didn't really stop us on offense. We were doing whatever we wanted. The biggest thing we had was turnovers."
Tillman got called for interference on a deep pass to Green that put the ball on the 1, and BenJarvus Green-Ellis plowed in from the 5 after being hit with a 4-yard loss, making it 21-10.
But the Bears responded with an 80-yard drive that ended with Forte running it in from the 1 to get them back within four.
Vontaze Burfict intercepted Cutler near midfield early in the fourth quarter, and took a shot to the right knee from Chicago's Kyle Adams.
"I didn't understand it. You know?" Marshall said. "Fourth quarter, put a safety on me one on one? You can only ask for that and dream about that."
The unnecessary roughness penalty that kept the drive going and allowed Cutler to take a knee twice, ending the game.
NOTES: Burfict said his knee was bruised. ... Green hurt a finger at one point, but Lewis said he's fine. ... Bengals LT Andrew Whitworth, recovering from offseason surgery on his left knee, was inactive. ... Gould held the previous Bears record with a 57-yard field goal against Denver on Dec. 11, 2011. ... Trestman joined Hall of Famer George Halas (1920), Neill Armstrong (1978) and Dick Jauron (1999) as the only coaches to win their Bears debut.
Copyright 2013 by The Associated Press