Clinging to a 23-21 in the fourth quarter, the 49ers drove the ball down the field in what looked like a much-needed scoring drive. However, with the 49ers threatening on first and goal, Mason was tackled for loss and fumbled the football. With six minutes remaining, the Cardinals took back over in the fourth quarter after Mason’s costly fumble.

Another fourth-quarter collapse led to another San Francisco 49ers’ loss against an NFC West rival on Sunday. Two weeks after faltering on the road to the Los Angeles Rams, the 49ers blew a 10-point lead and exited with a 24-23 loss to the Arizona Cardinals,