However, the big question is, will the Packers learn from the battle and become a team that will improve week by week and be running on all eight cylinders late in the season and in the postseason?
Here are just 10 things we learned from Sunday.
The Green Bay Packers allowed 186 yards rushing, with a rushing average of 5.8 yards. That type of performance won't win you many, if any, games in the NFL.
This is even worse than last season, when the Packers were ranked 32nd in total defense—including their 14th-ranked run defense, which gave up 1,789 rushing yards overall with a 4.7-yard rushing average.
The Green Bay Packers had the 27th-ranked rushing offense in the NFL last season, when the team rushed for 1,558 yards overall and a 3.9-yard rushing average.
The Packers only had 45 yards rushing on Sunday, and quarterback Aaron Rodgers had 27 of those yards, while new running back Cedric Benson only had 18 yards in nine attempts.
The Packers had a paltry rushing average of 3.2 yards.
Taken over 16 games, the Packers would only have 720 rushing yards total this season if that type of performance continues.
I've got news for you, just in case you didn't know. The San Francisco 49ers are a very good team. One can see why they were in the NFC Championship Game last year.
On offense, the Niners had great balance on Sunday, as they ran for 186 yards and threw for 191 more.
Alex Smith led an offense that didn't have any turnovers, while the defense was able to get a key interception in the fourth quarter.
The 49ers are an exceptional tackling team, and the Green Bay Packers were consistently taken down immediately after catching the football.
Aaron Rodgers had a game that many quarterbacks in the NFL would love to have on Sunday.
Rodgers finished with 30 completions in 44 attempts for 303 yards, two touchdowns and one costly pick for a QB passer rating of 93.3.
However, Rodgers could not hit on any deep passes, and the costly interception he threw in the fourth quarter was the key play of the game.
Rodgers had a 122.5 QB rating in 2011, which set an all-time NFL record. Rodgers only had a QB rating below 100 twice last season.
The Green Bay Packers had four sacks on Sunday vs. the San Francisco 49ers, with Clay Matthews getting 2.5 sacks and Charles Woodson getting the other 1.5.
Linebacker Nick Perry did have six tackles and brought some pressure at times, but more often than not, 49ers QB Alex Smith was given way too much time to find an open receiver.
Smith was 20-of-26 in passing for 211 yards, two touchdowns and zero picks for a 125.6 QB rating.
The Green Bay defense seemed to be on its heels all day long. It couldn't stop the run and gave up too many big plays in the secondary.
San Francisco 49ers quarterback Alex Smith carved up the secondary and had two touchdown passes vs. no interceptions for 211 yards and a QB rating of 125.6.
Tight end Vernon Davis also had three catches for 43 yards and another touchdown.
Randall Cobb started this season exactly how he started last season: by producing a return touchdown.
Last year vs. the New Orleans Saints, Cobb established a new NFL record by having a 108-yard kickoff return.
On Sunday, Cobb returned a punt for 75 yards an another touchdown.
The big difference was Cobb's performance in the passing game. Cobb had only two receptions for 35 yards and one touchdown vs. the Saints, while on Sunday, Cobb had nine catches for 77 yards.
Cobb was also used at times running out of sets in the backfield on Sunday. 2012 looks to be a big year for the second-year player from the University of Kentucky, who will be used in many different capacities.
If there was ever any doubt where veteran Donald Driver might be in the pecking order of Green Bay Packers wide receivers, the game on Sunday told you exactly where his place is.
Driver did not have one reception. Not one.
Meanwhile, Randall Cobb had nine catches, Jermichael Finley had seven, Greg Jennings and Jordy Nelson each had five catches and James Jones had four.
I'm sure Driver will get his opportunities this season, but it is clear that Cobb has moved into the top four options at wideout, while Driver is now option No. 5.
The NFL has to come to an agreement with the regular officials it has used in the past, because it is clear that the integrity of the league will be in question with the continued use of replacement officials.
It's become a joke. A bad joke. Missing obvious calls has become the norm.
I never thought that the regular officials were fantastic, but compared to these inept zebras, they certainly seem to be.
The Green Bay Packers can't hang their heads for too long after their loss on Sunday, as the 1-0 Chicago Bears will be at Lambeau Field on Thursday.
The Bears only allowed 63 rushing yards vs. the Indianapolis Colts and picked off rookie QB Andrew Luck three times in their 41-21 victory on Sunday.
Da Bears also rushed for 114 yards.
The Packers can't afford to start out 0-2 in 2012, including a loss to a divisional rival.