The team finished the regular season with a 13–3 record. The season was one of the franchise's most successful seasons to that point and was considered to be "the birth of a dynasty", when the 49ers began a decade of dominance over much of the NFL. The 49ers drew an average home attendance of 54,398 in the 1981 NFL season.
The 49ers won Super Bowl XVI by defeating the AFC Champion Cincinnati Bengals. It was the first of five Super Bowl victories in franchise history, all within the next 13 seasons. From 1981 to 1997, the 49ers would have 13 NFC West titles, 8 NFC top seeds, and 7 seasons as the NFL's best team.
With the offense in good shape, Walsh and the 49ers focused on overhauling the defense in 1981. Walsh took the highly unusual step of overhauling his entire secondary with rookies and untested players, bringing on board Ronnie Lott, Eric Wright and Carlton Williamson and giving Dwight Hicks a prominent role. He also acquired veteran linebacker Jack "Hacksaw" Reynolds and veteran defensive lineman and sack specialist Fred Dean.
These new additions, when added to existing defensive mainstays like Keena Turner, turned the 49ers into a dominant team. After a 1–2 start, the 49ers won all but one of their final games to finish with a 13–3 record, easily the best record in the team's history. Additionally, the 49ers defense yielded more than 20 points in only three games. Dean and Hicks made the Pro Bowl. The 49ers selection of Lott in the 1981 NFL Draft proved to be a seminal one. In addition to making the NFC Pro Bowl roster, Lott was voted First-Team All-Pro and received nods from all 5 newspapers that voted, a significant honor for a rookie. Giants' linebacker Lawrence Taylor was the only other rookie from the 1981 NFL Draft to achieve this unanimous selection to the First Team All-Pro unit.
Led by Montana, the unusual offense was centered around the short passing game, which Walsh used as ball control. Both Dwight Clark and Freddie Solomon had excellent years receiving; Clark as the possession receiver, and Solomon as more of a deep threat. The 49ers running game, however, was among the weakest for any champion in NFL history. Ricky Patton led the 49ers with only 543 yards rushing. The 49ers' most valuable running back, however, might have been Earl Cooper, whose strength was as a pass-catching back (he had 51 catches during the season).
The Giants were making their first appearance in the postseason since 1963. First-year starting quarterback Joe Montana led the 49ers to victory in his debut playoff game, completing 20 of 31 passes for 304 yards and 2 touchdowns, with 1 interception. His top target in the game was receiver Dwight Clark, who caught 5 passes for 104 yards.
NFC Divisional Playoff: New York Giants at San Francisco 49ers – Game summary
The 49ers were making their third appearance in the NFC Championship Game. Their opponent was their opponent for the two previous NFC Championship Games-the Dallas Cowboys. In both previous matches, the 49ers had lost the game. The game is remembered for "The Catch".
The play, remembered in 49er lore as "Red Right Tight—Sprint Right Option" had called for both the primary receiver, Solomon, and Dwight Clark to line up on the right. Montana was supposed to roll to his right and find Solomon. Clark's pattern called for him to cut left across the end zone, stop, and immediately reverse his path to the right. If Solomon were covered, it would be up to Montana to find Clark. Due to the pressure, Montana's pass was high, but Clark was in position to make his memorable grab. Future New England Patriots/Tampa Bay Buccaneers quarterback Tom Brady, who grew up in the Bay Area, attended the game as a four-year-old. The 49ers were victorious despite an astonishing six turnovers, including three interceptions by Joe Montana.
A photograph of the catch, with Clark at the height of his leap and Everson Walls reaching out to try to block the ball, was featured on the cover of Sports Illustrated the following week.
NFC Championship Game: Dallas Cowboys at San Francisco 49ers – Game summary