How it unfolded
San Francisco, 2–14 two seasons earlier, arrived 13–3 to face the team that had owned the NFC through the 1970s. The lead changed six times; the 49ers turned the ball over six times. Trailing 27–21 with 4:54 left, they started from their 11. Joe Montana mixed short passes and runs for 89 yards in 13 plays; facing third-and-3 at the Dallas 6 with 58 seconds left, he rolled right away from Ed 'Too Tall' Jones and lofted a pass toward the back of the end zone. Dwight Clark fully extended to fingertip-catch it; Ray Wersching's extra point made it 28–27. Dallas still had a chance — Danny White hit Drew Pearson for 31 yards, but Pearson fumbled on the next play and Jim Stuckey recovered to end it. Two weeks later San Francisco beat Cincinnati 26–21 in Super Bowl XVI.
Why it still matters
A rare case where one play marks the end of one dynasty and the start of another. Walsh's West Coast offence became validated system; San Francisco won five Super Bowls in the next 13 years. Dallas drifted from championship contention for more than a decade after this loss. 'The Catch' needs no explanation as a proper noun.