The Bears erased a 10-point third-quarter deficit by scoring 19 unanswered points to beat the 49ers 19-10 in the season opener Sunday at Soldier Field.

After a sluggish start, quarterback Justin Fields threw a pair touchdown passes in the second half to Dante Pettis and Equanimeous St. Brown, and a fourth-quarter interception by safety Eddie Jackson set up a Khalil Herbert rushing touchdown.

Coach Matt Eberflus earned his first win as an NFL head coach and expressed his excitement about starting 1-0.

"It's a happy feeling. It really is; when you see they're out of timeouts and the clock's going down and the rain is coming down," Eberflus said. "And it's a good feeling. It was exciting and for the first victory, and I'm excited for the guys, too. I'm excited for everybody: offense, defense, kicking. I'm excited for the organization. It was fun."

Fields threw for just 19 yards in the first half, completing 3 of his 9 pass attempts. The second-year quarterback finished the game with 8 of 17 completions for 121 yards and the two scores, earning an 85.7 rating.

"I think we were just trying to find a rhythm [in the first half]," Fields said. "The offense, at least, we were dealing with long fields and our defense did a great job dealing with the short fields that they got, [held] them in the red zone for three points on one of the drives.

"We were backed up so when you're backed up like that, you just can't use the whole playbook. But the second half, we found a rhythm and we executed, so I'm proud of the guys."

The Bears defense excelled throughout the entire game, generating two takeaways. They held the 49ers to three points in the second half and held quarterback Trey Lance to a 46.4 completion percentage and a 50.3 rating.

The 49ers drove to the Bears 16 on their first drive of the game before Jaylon Johnson punched the ball out of the hands of receiver Deebo Samuel, which was recovered by rookie safety Jaquan Brisker.

"That was great. Their own drive, they had some momentum and we stopped it with that," Eberflus said. "That happens. I can go back to countless examples where the guys get in the red zone. If you just hang in there on defense and you keep pounding the rock, good things will happen, and that's what happened. Jaylon punched it, Brisker recovered it. It was an outstanding play. That happens a lot of times on the perimeter. The ball comes off the body and you get a punch out."

San Francisco's defense quickly got the ball back as Talanoa Hufanga intercepted Fields at the Chicago 49.

After a scoreless first quarter, the 49ers reached the end zone with 10:17 to play in the first half. The drive was led by Lance's 20-yard pass to Ray Ray McCloud. On the subsequent third down, defensive tackle Justin Jones was offsides, giving the 49ers a first down at the four-yard line. Samuel then found the end zone from six yards out to give San Francisco a 7-0 lead.

The 49ers increased their lead to 10-0 on the first drive of the third quarter as Robbie Gould kicked a 25-yard field goal. Lance's 44-yard pass to receiver Jeff Wilson Jr., who beat cornerback Kyler Gordon downfield, put the 49ers at the Chicago 16. Lance rushed for another first down on the drive, but linebacker Roquan Smith and rookie defensive end Dominique Robinson teamed up for a sack on third down to hold the 49ers to the field goal.

Fields then orchestrated the Bears' first scoring drive of the day. On third down, his throw to St. Brown was incomplete, but a 49ers' facemask penalty kept the drive alive.

Two plays later, Fields escaped the pocket and rolled to his left, finding Pettis wide open across the field. The pair connected for a 51-yard touchdown pass, cutting into the 49ers lead at 10-7.

"What a great play, the vision by Justin to see that and throw it back there was a great play," Eberflus said. "And that's the kind of plays he can make. That's what makes him dangerous because he can throw on schedule throws, but man he's got the off-schedule throws too and we've always said he's that he's an outstanding deep ball thrower. He can throw the ball deep, accurately, so we're all excited about that play for sure."

After the Bears defense forced a punt, Fields engineered 10-play, 84-yard touchdown drive. The quarterback opened the series with a 22-yard pass to receiver Byron Pringle. On third down, Fields scrambled and was hit while sliding, resulting in a 15-yard penalty and a Bears first down at the San Francisco 41.

Fields then hit St. Brown in the end zone for an 18-yard score. Kicker Cairo Santos missed the extra point, but the Bears took a 13-10 lead with 12:45 left in the game.

On the 49ers next drive, Jackson intercepted Lance and returned it 26 yards to the San Francisco 21, setting up the Bears' third TD. On second down, Herbert rushed for five yards, and defensive holding penalty on the same play led to a Bears first down at the 3.

Herbert then found the end zone from three yards out, building the Bears lead to 19-10 after another missed extra point.

"We had a little bit of rough sledding in the first half, and I thought that the guys came out in the second half and gained some momentum in that drive right before halftime," Eberflus said. "I thought that was really good. The defense in the first half gave up a couple of plays. We had to shore some things up in the halftime, so we did that. So I thought the guys did a nice job at halftime and it's a four-quarter game. You've got to play the second half, and that's what we're built for.

"We always tell the guys, 'hey, we have mental and physical stamina for what reason?' And it is because of the way we practice and the way we play and we're able to stay focused when it is the second half in those critical moments and they can play and be focused in those moments, so that was really good."