The 1958 championship game was the first NFL playoff game to go into sudden death overtime. Featuring a who’s who of gridiron legends including Johnny Unitas and Frank Gifford, the contest between the Baltimore Colts and the New York Giants was played at Yankee Stadium in The Bronx and attracted a national television audience. Professional football at that time was rising in popularity, but was playing second fiddle to the likes of baseball and boxing in terms of sports viewership. The game would later become known in football lore as “The Greatest Game Ever Played.” More importantly, the game captured the collective attention of the nation and as a result, and pro football exploded across the country in the following years. By the mid-1960s, professional football became the nation’s favorite sport to watch and has remained on top ever since.
Both teams finished the 1958 season with a 9–3 record. For the Giants, it was their fifth consecutive winning season, a stretch that included an NFL Championship in 1956. In contrast, 1958 was only the second winning season in Colts' history since the team's founding in 1953.
Baltimore started off the season winning their first six games before losing to New York, 24–21, in week 7 of the regular season. However, Colts starting quarterback Johnny Unitas was injured at the time and did not play in the game. Three weeks later, Unitas returned to lead the Colts to a critical come-from-behind win against Hall of Fame quarterback Y. A. Tittle and his San Francisco 49ers. Trailing 27–7 at halftime, Baltimore stormed back with four unanswered touchdowns to win, 35–27, clinching the Western Conference championship. This allowed them to rest their starters for the final two games of the regular season, both on the road in California.
New York started the season 2–2, then won seven of their last eight games, including a critical 19–17 win over the defending champion Detroit Lions on December 7. In that game, New York fell behind late when the offense lost a fumble that was returned for a touchdown. Later on, however, the Giants stopped Detroit punter Yale Lary on a fake punt attempt and drove for the go-ahead score. They then secured the win by blocking a Lions field goal attempt as time expired in the game. In the final game of the regular season, the Giants defeated the Cleveland Browns with Pat Summerall's game-winning 49-yard field goal on the final play (the longest field goal made in the entire season among all NFL kickers). The win enabled them to tie the Browns for the conference title, and though the Giants had won both games against Cleveland in the regular season, the rules of the time required a tiebreaker playoff game on December 21. At Yankee Stadium in 20 °F (−7 °C) weather, the Giants defeated the Browns for a third time in a shut out
After clinching their conference title on November 30, the Colts rested key players in the final two games, road losses in California. Baltimore had a week off and entered the title game as 3½ point favorites to gain their first league title.