The Chicago Bears felt the need to make a statement about their ability to be competitive with a Super Bowl contender.
They did so on Sunday night at Soldier Field, and their defense did most of the talking.
"What I'll say is we just had it tonight," Bears defensive tackle Akiem Hicks said. "We had a lot of heart, we had a lot of focus and we pulled it out."
The Bears defense deodorized a foul night by quarterback Mitchell Trubisky (three interceptions) in his return from a shoulder injury. Against one of the league's top offenses, the Bears recorded a strip sack by Mack, a safety by Eddie Goldman and interceptions from rookie Roquan Smith, Eddie Jackson, Prince Amukamara and Kyle Fuller.
"All 11 guys collectively going against the offense, it was going to be a big challenge for us," Mack said. "We stepped up to the challenge."
The key defensive swing came late in the third quarter with Chicago leading 15-6, when Trubisky threw high for an interception by John Johnson and a 28-yard return to the Bears' 27. On the next play, Fuller made his sixth interception of the season on a floating Goff throw near the sideline and the Bears (9-4) had dodged a potential disaster.
"It was just playing technique and fundamentals and the defense called, and being in position," Fuller said. "[The Rams] have been doing it, but we challenged ourselves to come in and do what we had to do and I think we did a good job
"We're just getting better together."
The Rams (11-2) only seriously threatened again once after that, but kicker Greg Zuerlein bumped one off the right upright for a miss with 10:13 left.
"Our play on defense, all I can say is wow," Bears coach Matt Nagy said.
Leading the NFL in average yardage starting the game, the Rams gained only 214 yards and the Bears' third-ranked defense sacked Goff three times, once each by Mack, Hicks and Goldman. Gurley finished last week as the NFL rushing leader but was held to 28 yards on 11 carries.
Goff finished 20-of-44 for 180 yards with four interceptions and a 19.1 passer rating.
"They did a great job defensively," Goff said. "They had a good scheme for us and did a good job, but we have got to be better and that starts with me. And I've just got to be better in a lot of different things."
Earlier in the third quarter, the Bears defense broke a 6-6 tie when nose tackle Goldman broke free up the middle and threw Goff to the ground in the end zone for a safety.
After the ensuing free kick, the Bears drove 81 yards to their touchdown on a 2-yard, tackle-eligible pass to Bradley Sowell. The Bears lined up in a lineman-heavy formation with Hicks at tailback, and Truibisky faked the handoff and threw to Sowell in the right corner on a play they named "Santa's Sleigh."
"We needed a play, so they went to the play maker," joked Sowell, a 6-foot-7, 312-pound backup tackle.
"Christmas came early," Trubisky said.
The loss dropped the Rams behind the New Orleans Saints in the race for top seed in the NFC. Both are 11-2 but the Saints beat the Rams earlier this season.
"I'll look at myself critically," Rams head coach Sean McVay said. "And I'll make sure that I learn from a lot of the bad decisions that I did make for us.
"So whatever I was deciding on tonight clearly wasn't putting our players in good spots. ... They're a great defense but I think the issue starts with me."
Trubisky went 16-of-30 for 110 yards, but the Bears ran for 194 yards on 35 carries, including 101 yards on 19 tries by Jordan Howard as he ended a streak of 15 straight games without a 100-yard effort.
"We got into a rhythm in the second half," Howard said.
Neither offense could get established early, as both defenses controlled the first half.
Smith intercepted a pressured throw by Goff and returned it 22 yards to the Rams' 4-yard to set up a Cody Parkey 31-yard field goal in the second quarter.
But the Rams tied it at 6-6 on Zuerlein's 50-yard after a fake punt resulted in a 7-yard completion by punter Johnny Hekker and a first down by inches.
"It's definitely tough to play in a big-time game like that and not play well and not win and not do what you want to do," Goff said. "But at the same time, we're 11-2, we won the division with three weeks left and have everything in front of us. And I feel really good about that."