In a commanding performance, the San Francisco 49ers blanked the Arizona Cardinals 31-0 in Week 4 of the 2027 season. The stakes were high as both teams aimed to solidify their playoff positioning, but it was the 49ers who demonstrated their dominance on both sides of the ball, leaving the Cardinals struggling to find their rhythm. Brock Purdy led the charge for San Francisco, throwing for 221 yards and a touchdown, showcasing his precision in the pocket. Meanwhile, Christian McCaffrey was a dual threat, racking up 84 rushing yards and adding another 80 through the air, proving instrumental in the 49ers' offensive scheme. His ability to make plays in crucial moments kept the Cardinals on their heels throughout the game. Defensively, the 49ers were relentless, with Nick Bosa spearheading the effort. Bosa tallied an impressive 4.5 sacks and contributed four total tackles, wreaking havoc on the Cardinals' offensive line. The turning point came early in the second half when Bosa's relentless pressure led to a turnover, allowing the 49ers to extend their lead and effectively put the game out of reach for Arizona.