On the biggest stage the 49ers have faced this season, quarterback Jimmy Garoppolo delivered an impressive performance to help lead San Francisco to a 26-21 Week 17 win at CenturyLink Field over the Seattle Seahawks.

The win was a de facto playoff game, as the Niners clinched the No. 1 seed in the NFC and won the team’s first NFC West crown since 2012.

How will Jimmy G fare in his first postseason start when the 49ers host a divisional-round game on Jan. 11?

“Listen, what more questions can we have about the guy?” NBC Sports’ Chris Simms said. “He just probably played the toughest month of December in the history of any quarterbacks ever.

“We saw how he acted and how he played. He was unfazed by it, he played one of his better games of the whole season up in Seattle, in an incredibly tough environment.”

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Jimmy G completed 18-of-22 passing attempts for 285 yards in that division-clinching victory, not showing any cracks under the pressure of trying to win in front of the vaunted “12th man.”

San Francisco will find out its first playoff opponent Sunday, as the Niners will host the lowest remaining seed from the two NFC games on wild card weekend.