It was the most anticipated game of the new 1966 season. It became the launching point for one of the great single seasons by a quarterback in NFL history.
A championship rematch brought the Packers and Cleveland Browns together by Lake Erie on a warm September afternoon in the second week of the season.
Even without Jim Brown (who had retired), the Browns stormed to a 14-0 lead in the first two quarters, as Frank Ryan hit Gary Collins for two touchdown passes.
Then, eventual 1966 NFL MVP Bart Starr led a comeback with two fourth-down touchdown passes to fellow future Pro Football Hall of Famers.
The first was a staple of the Lombardi offense which prided itself on gaining tough yards through the run game, and defenses attempting to stop them.
Starr faked a handoff on fourth-and-1 and delivered a 44-yard strike to Paul Hornung, one which cut the lead in half at 14-7.
Then, down 20-14 with minutes left, Starr led a methodical but time-conserving 14 play, 85-yard drive.
The drive was nine yards away from success on 4th-and-goal with 2:00 left.
With no receivers open in the end zone, Starr went to his outlet, fullback Jim Taylor who was seven yards from victory, with two Browns in his way.
Taylor sent them groundward like rag dolls on his way to the the end zone. Don Chandler nailed the extra point to give the Packers a hard-fought 21-20 win in Starr's 13th 4th-quarter comeback as a Packer.
Starr completed 62.2 percent of his passes in 1966 for 2,257 yards, 14 touchdown passes and just three interceptions for a 105.0 passer rating.
Now, Starr's rating for that year ranks 34th all-time in NFL history, but at the time it was an otherworldly performance that ranked fourth in league annals.
Starr's 105.0 was also 45 passer rating points above the median passer rating for NFL starters that year, 75 percent better than the middle-of-the-road quarterbacking performance.
That performance was even better than Aaron Rodgers' 41.5 passer rating points above the median during his record-setting year of 2011 (51.2 percent better than the median).
In other words, Starr was even better than his quarterbacking co-horts in 1966 than Rodgers was in his best season, revealing how incredible Starr was in that 1966 campaign.
And that's beyond the clutchness of performances like Starr on this sunny September day in Cleveland, the first big step toward Green Bay's second consecutive championship.