Table:
text: 1957 Green Bay Packers season
Schedule
Schedule
Week Date_ Opponent Result_ Venue Attendance
9 November 24, 1957 at Pittsburgh Steelers W 27-10 Forbes Field 29701
10 November 28, 1957 at Detroit Lions L 18-6 Briggs Stadium 54301
11 December 8, 1957 at Los Angeles Rams L 42-17 Los Angeles Memorial Coliseum 70572
12 December 15, 1957 at San Francisco 49ers L 27-20 Kezar Stadium 59100

Question: Which San Francisco 49ers opponent had the worst week of the Green Bay Packers' 1957 season?