SANTA CLARA – The Packers defense was the star against an opponent that was previously unstoppable.

“Our defense played lights out. I think it was our best performance this year,” Packers Head Coach Mike McCarthy said following a 17-3 win at Levi’s Stadium on Sunday.

It was an especially satisfying victory because it was against no less an antagonist than Colin Kaepernick and the San Francisco 49ers, both of whom had dominated the Packers in recent outings. Kaepernick led the 49ers to postseason wins over the Packers in the 2012 and ’13 seasons.

In this game, the Packers dominated Kaepernick as Kaepernick had terrorized the Packers in the ’12 playoff game. The Packers sacked Kaepernick six times on Sunday. Following one of Clay Matthews’ two sacks, he kissed his right bicep, a gesture Kaepernick made famous in the ’12 playoff game, one of the darkest days in Packers defense history.

“It’s a different year and a different offensive coordinator. We looked at what had caused us problems in the past. I thought Dom Capers was aggressive throughout the whole game,” McCarthy said.

Capers, the Packers defensive coordinator, was harshly criticized for Kaepernick’s performance in that ’12 playoff game. In Sunday’s game, Capers’ defense played with razor’s edge-like effectiveness. It held Kaepernick to 160 yards passing and just 57 yards rushing. On several occasions, the young quarterback appeared dazed and confused, throwing wildly and making curious decisions.

Packers quarterback Aaron Rodgers praised the Packers defense for being the difference maker on a day when the Packers passing game was less effective than usual.

“Any time you’re under that kind of pass rush, it’s tough to be effective,” Rodgers said in explaining the challenge Kaepernick faced. “We needed that type of effort because we were a little bit off today. We had some guys that didn’t have their best days today.”

Kaepernick’s final line reads: 13 of 25, 160 yards, one interception and a 55.4 passer rating.

Rodgers was effective, if not his usual scintillating self: 22 of 32, 224 yards, one touchdown and a 99.0 passer rating.

“It was a grind. We had a good first drive and we kind of stalled for a while. The defense played incredible. We were effective running. We have to do a little better job throwing it and catching it. But it was a good win for us,” Rodgers said.

“Excited to get to 4-0. That’s the most important part. Going back to when the schedule came out, we knew this would be a tough, tough battle. Very pleased with our football team,” McCarthy said.

The Packers return home for games against visiting St. Louis and San Diego. They’ll have a chance to take a 6-0 record into the bye week, setting the stage for a November and December run at homefield advantage for the playoffs, and maybe even more. Do we dare think it? Not yet.

“Looking forward to going back home and getting on a seven-day week,” McCarthy said, his team having come off a Monday night game and a long road trip.

“I thought our energy was excellent. It’s something we talked about as a team. We’re just looking for ways to improve and I think we hit the target,” McCarthy added.

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