Super Bowl X Super Bowl X Super Bowl X was an American football game between the National Football Conference (NFC) champion Dallas Cowboys and the American Football Conference (AFC) champion Pittsburgh Steelers to decide the National Football League (NFL) champion for the 1975 season. The Steelers defeated the Cowboys by the score of 21–17 to win their second consecutive Super Bowl. They were the third team to win back-to-back Super Bowls. (The Miami Dolphins won Super Bowls VII and VIII, and the Green Bay Packers won Super Bowls I and II.) It was also the first Super Bowl in which both participating teams
Miami Dolphins losing to the Dallas Cowboys, 24–3. The following year, the Dolphins completed the NFL's only perfect season, culminating in a Super Bowl win, winning all 14 of their regular season games, and all three of their playoff games, including Super Bowl VII. The 1972 Dolphins were the third NFL team to accomplish a perfect regular season, and won Super Bowl VIII, becoming the first team to appear in three consecutive Super Bowls, and the second team (the first AFL/AFC team) to win back-to-back championships. Miami also appeared in Super Bowl XVII and Super Bowl XIX, losing both games. For most