Although the $5.5 billion Sofi Stadium opened last year, fans were not allowed in the stands that season due to the pandemic.
Matthew Stafford's Rams debut seemed to validate the team's decision to trade for him in the offseason as he threw for 321 yards on 20/26 completions and three touchdowns.
Matt Gay made two field goals and Darrell Henderson Jr. ran in a touchdown among his 16 carries for 70 yards
In his postgame interview, Stafford praised SoFi and the Rams fans who came out for the opener.
"The people of LA filled it and were loud for us which was just amazing," Stafford said.
The Rams welcomed fans to SoFi during a festive evening that included appearances by former Rams stars Jackie Slater, Torry Holt, Orlando Pace, Jim Everett and Steven Jackson. OneRepublic played a halftime show.
League veteran Andy Dalton started for the Bears, passing for 206 yards in his Chicago debut. Rookie quarterback Justin Fields rushed for a 3-yard score while getting a handful of snaps in his NFL debut.
Chicago moved the ball steadily, but Dalton's end-zone interception after a solid opening drive left the Bears playing from behind all night.
Dalton has begun his Bears career in a competition with Fields, the touted Ohio State rookie who looked impressive in the preseason. Nagy used both quarterbacks against the Rams, intermittently substituting Fields from the opening drive onward. Fields completed both of his passes for 10 yards.
Next Sunday the Rams face the Colts in Indianapolis.
The Associated Press contributed to this report.