The Dolphins were led by legendary head coach Don Shula. With Bob Griese at quarterback and Larry Csonka at fullback, the Dolphins opened the season with high expectations. Although, as everyone knows, the Dolphins did make it through the season without a loss on their record, the road was not always smooth sailing and the games were often not decided until the fourth quarter.
Miami started the season by helping the Kansas City Chiefs open the new Arrowhead Stadium in Kansas City. The Dolphins handled the Chiefs fairly easily, defeating them 20-10, with the Chiefs scoring their only touchdown with nine seconds to play in the game. Larry Csonka led the way with 118 yards rushing and scored one touchdown, while Griese chipped in with a touchdown pass to Marlin Briscoe. Week two was no different as Miami dominated the Houston Oilers, 34-13.
Week three brought the first close call of the season for the Miami Dolphins. They were playing Minnesota, and the Vikings had the upper hand most of the game. The Dolphins were trailing, 14-6 in the fourth quarter before Garo Yepremian connected on a 51-yard field goal attempt to make the score 14-9. After the Vikings offense bogged down, the Dolphins took possession of the ball and Griese led them down the field. The drive culminated in a three-yard touchdown pass from Griese to tight end Jim Mandich with 1:28 left on the clock. The Dolphins, at the time, were the only undefeated team left in the league.
Miami pulled off easy victories over the Jets in week four and the Chargers in week five, but the victory over San Diego came at a huge cost. Quarterback Bob Griese suffered the fracture of a small bone in his right leg, and he also dislocated his right ankle. Griese was replaced by 38-year old Earl Morrall, and in his first full game the veteran backup barely slipped the Dolphins past the Buffalo Bills. Morrall, relying heavily on the running game, threw only ten passes the entire game, completing six of them for 91 yards.
Miami went into cruise control the next three games, recording two shutouts and outscoring their opponents, 105-16. They would not be tested again until week ten in a rematch with the New York Jets. With a chance to clinch the AFC East title, the Dolphins found themselves trailing the Jets, 24-20 as the fourth quarter started. But Mercury Morris, who rushed for 107 yards during the game, would not be denied as he scampered fourteen yards into the end zone for the go-ahead score. The Dolphins clinched the AFC East title, and were the proud owners of a 10-0 record.
The Dolphins finished off the final four games of the season in dominant fashion. They knocked off the Cardinals, 31-10, the Patriots, 37-21, and then the Giants, 23-13. In week fourteen, the final week of the regular season, the Dolphins beat Baltimore, 16-0, in a game that turned out to be Johnny Unitas' last with the Colts. Not since the Chicago Bears finished the season undefeated thirty years earlier had a team finished the regular season schedule without a loss.
In the first round of the playoffs, Miami was able to slip past the Browns as Paul Warfield slipped past defenders for sixty of the eighty yards in the Dolphins game-winning drive.