ST. LOUIS (AP) -- The only time the brother vs. brother subplot got really physical was when Chris Long played the role of peacemaker.
Racing off the sideline where he'd taken a play off, the St. Louis Rams defensive end rescued a teammate and dragged Chicago Bears guard Kyle Long out of a first-half fracas before it could escalate.
''One way to defuse that situation was to get everybody out of there,'' Chris Long said. ''He happened to be a body I saw, so I grabbed him.''
Until they posed for photos after the game with Mom and Dad after the Rams outmuscled the Bears 42-21 on Sunday, it had been mostly just another game day. They lined up close to each other all day, and traded the occasional glancing blow.
''It's not like we went head to head much,'' Chris Long said. ''I'm sure there's some out there disappointed with it if they were glued to the TV looking for conflict between us.''
There was plenty between the Bears and Rams, though.
Tavon Austin's 65-yard touchdown run - his fourth straight this season from beyond midfield - jump-started a 21-point first quarter and the defense made some big plays, too.
Coming off their bye, the Rams (5-6) followed up a 30-point rout of Indianapolis in front of their first capacity crowd of the season, about half of them clad Bears orange. Late scores by rookie backup running back Benny Cunningham and defensive end Robert Quinn helped finish off the Bears (6-5), who remained tied for the NFC North lead.
''Guys are fighting,'' Quinn said. ''We know we can make a run.''
Josh McCown passed for 352 yards and two touchdowns with an interception for Chicago, which had won four straight in the series. The Bears were dogged by penalties throughout, including a 62-yard punt return for touchdown by Devin Hester nullified by a holding call in the fourth quarter.
On the play that ended with his big brother dragging him off the field, Kyle Long said he'd been reacting to a cheap shot in the back ''about 30 yards away from the play.'' He had defensive end William Hayes down and delivered some forearm blows before Chris Long intervened.
''I still don't know if there was a whistle. Some of the guys said there was,'' Kyle Long said. ''You can't lose your cool, and I lost my cool.''
Kyle Long got a personal foul and there were two other major penalties declined on the play, intentional grounding on McCown and a facemask call on fullback Tony Fiammetta.
Cunningham's 9-yard run with 3:05 to play plus a 2-point conversion pass from Kellen Clemens to Isaiah Pead put the Rams up 35-21. Quinn stripped McCown on a sack and then scooped up the ball on a 31-yard return just before the 2-minute warning for his first career NFL touchdown.
The Bears had first-and-goal at the 4 on their opening drive of the second half trailing 24-14 and got nothing when coach Marc Trestman decided against a field goal and Michael Bush was thrown for a 4-yard loss by Jo-Lonn Dunbar.
''We always talk on goal-line defense about never conceding anything,'' Dunbar said. ''The second time they had too many opportunities and they finally got that one in. But we pride ourselves in holding them.''
Kyle Long took the blame, saying ''I didn't pull far enough. That one falls on me.''
Cunningham rushed for 109 yards on 13 carries, most of it in the second half after Zac Stacy was sidelined with concussionlike symptoms. Cornerback Trumaine Johnson and guard Chris Williams also left following blows to the head.
McCown's passing yardage total was the third-best of his career and most since 2005.
The Rams stunned the Bears early with two big plays and two touchdowns.
Austin reversed field on a pitchout for a 65-yard run that gave them points on their opening possession the first time all year. Stacy's 1-yard run capitalized on a lost fumble by Matt Forte at the 7 for a 14-0 cushion with 12:36 to go in the first quarter.
Jared Cook added a 6-yard catch from Clemens late in the first for a 21-7 cushion, offsetting Martellus Bennett's 7-yard reception from McCown.
The Rams totaled 29 points in the first quarter during the first 10 games before surging against a defense that been on the upswing, allowing an average of 20 points the last three games.
Brandon Marshall got free with a little push off Janoris Jenkins on a 3-yard catch that cut the gap to 21-14 with 5:19 to go in the half.
Notes: Forte had 77 yards on 16 carries and has 6,178 with the Bears, passing Neal Anderson for second on the franchise career list behind Walter Payton, who had 16,726. ... The previous best paid attendance for the Rams was 56,640 for the 49ers in a Thursday night loss on Sept. 26.
AP NFL website: www.pro32.ap.org