The Colts arrived as 3.5-point favorites, riding the arm of quarterback Johnny Unitas, who had engineered a legendary comeback against Y.A. Tittle's San Francisco 49ers three weeks earlier - erasing a 27-7 halftime deficit to win 35-27 and clinch the Western Conference. Baltimore then rested its starters through the final two games, entering the championship fresh and confident. The Giants took a harder path. After a 2-2 start, they won seven of their last eight, including a harrowing 19-17 victory over the defending champion Detroit Lions - secured by blocking a field goal as time expired. In their final regular-season game, Pat Summerall's 49-yard field goal on the last play beat Cleveland, the longest successful kick by any NFL kicker that year. Because the rules required a tiebreaker, the Giants then shut out the Browns 10-0 at Yankee Stadium in 20-degree weather to earn their spot.

The first half was chaos. Six turnovers - three per team - set the tone as Baltimore converted two Frank Gifford fumbles into touchdown drives. Both fumbles were forced by defensive back Milt Davis, who played the entire game on two broken bones in his right foot. By halftime the Colts led 14-3, and the game seemed to be slipping away from New York. Then came the third quarter's pivotal sequence: Baltimore drove to the Giants' 1-yard line but was stopped cold. On fourth down, linebacker Cliff Livingston tackled Alan Ameche on a halfback option play at the 5. Momentum reversed instantly. Four plays later, the Giants had covered 95 yards, highlighted by an 86-yard pass play in which Kyle Rote fumbled at the Colts' 25 after breaking a tackle, only for trailing teammate Alex Webster to scoop up the loose ball and carry it to the 1. Mel Triplett punched it in.

New York took a 17-14 lead early in the fourth quarter on Charley Conerly's 15-yard touchdown pass to Gifford, the first time an NFL championship team had rallied from a deficit of more than 10 points to take the lead. Baltimore squandered two scoring chances - a missed 46-yard field goal and a drive killed by consecutive sacks from Andy Robustelli and Dick Modzelewski. With just over two minutes remaining and the Giants clinging to their lead, New York punted from its own 40. On the play before the punt, Marchetti suffered his broken ankle but refused a stretcher to the locker room. Unitas took over at his own 14-yard line and orchestrated what would later be recognized as the prototype two-minute drill. After two incompletions, he hit Lenny Moore for 11 yards on third down, then threw three consecutive passes to Raymond Berry - covering 62 yards total - to reach the Giants' 13. Steve Myhra's 20-yard field goal with seven seconds left tied it at 17.

No NFL playoff game had ever gone to overtime. Don Maynard muffed the opening kickoff for the Giants but recovered at the 20, and New York went three-and-out. Then Unitas went to work one more time, calling every play himself as he marched the Colts 80 yards in 13 plays against an exhausted defense. Ameche caught a critical 8-yard pass on third-and-8, then ripped off a 22-yard run to the Giants' 20. Berry hauled in two more catches for 33 yards. At one point, with the Colts on the 8-yard line, a spectator ran onto the field, halting play. Rumors persist that it was an NBC employee buying time after the national television feed went dead - an unplugged cable had killed the signal. Ameche finished the job with a 1-yard touchdown plunge, and the Colts won 23-17. Seventeen individuals from this game would eventually enter the Pro Football Hall of Fame, including the Giants' two coordinators: offensive coordinator Vince Lombardi, who left for Green Bay weeks later, and defensive coordinator Tom Landry, who would build the Dallas Cowboys dynasty.

The game's impact extended far beyond the final score. Within a year, Texas billionaire Lamar Hunt formed the American Football League, directly inspired by the public appetite this championship revealed. The eventual AFL-NFL merger, the explosion of television contracts, the Super Bowl itself - all trace a line back to this December afternoon in the Bronx. NFL Commissioner Pete Rozelle later credited the game's transformative power to timing and geography: it "happened just at that time, in that season, and it happened in New York." The audience of 45 million could have been larger still, but NFL blackout rules prevented the broadcast in the New York City market. Writer Mark Bowden, who authored a book on the game's 50th anniversary, found that the surviving players universally agreed on one thing: whatever they thought about the "greatest" label, the popularity of professional football exploded after that season, and nothing was ever the same.