The 49ers did their part by beating the Commanders in Week 17, and the Cardinals beating the Eagles helped, too.
The San Francisco 49ers are going to be the No. 1 seed in the NFC playoff picture after three things happened over the course of Week 17.
First, the Detroit Lions suffered a loss to the Dallas Cowboys, which dropped Detroit to 11-5.
Then, the Niners went on the road and beat the Washington Commanders 27-10 on Sunday to improve to 12-4.
All that remained was for head coach Kyle Shanahan's squad to get a little bit of help from an NFC West division rival.
Cardinals beat Eagles, 49ers secure No. 1 seed in NFC as a result
San Francisco had to dip into the locker room fairly quickly at FedEx Field after beating Washington in order to do some scoreboard watching between the Arizona Cardinals and the Philadelphia Eagles, which seemed to be a matchup that was wholly in Philly's favor.
Yet Arizona managed to pull off a thrilling 35-31 victory in a back-and-forth game at Lincoln Financial Filed to drop Philadelphia to 11-5 on the season.
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With the 49ers already owning the tiebreaker over the Eagles by beating them earlier this season, even if the Niners lose their Week 18 matchup against the Los Angeles Rams and Philly wins its regular-season finale, an identical record between San Francisco and Philadelphia would still go to the 49ers' favor.
As a result, the Niners not only have the No. 1 seed in the conference, but they also get a first-round bye in the playoffs and home-field advantage all the way to the Super Bowl.