The New York Giants and The Denver Broncos were the two teams fighting it out at Super Bowl XXI. Denver Broncos' Rich Karlis opened the scoring with a Super Bowl record tying 48 yard field goal. New York Giants drove 78 yards in nine plays on the next series to take a 7-3 lead on quarterback Phil Simms's 6-yard touchdown pass to tight end Zeke Mowatt. The Broncos came right back with a 58-yard scoring drive on six plays capped by Elway's 4-yard touchdown run. The only scoring in the second period was the sack of Elway in the end zone by defensive end George Martin for a New York safety. The Giants produced a key defensive stand early in the second quarter when the Broncos had a first down at the New York 1-yard line, but failed to score on three running plays and Karlis's 23-yard missed field-goal attempt. The New York Giants took command of the game in the third period en route to a 30-point second half, the most ever scored in one half of Super Bowl play.

New York took the lead for good on tight end Mark Bavaro's 13-yard touchdown catch five minutes into the third period. The nine-play, 63 yard scoring drive included the successful conversion of a fourth and 1 play on the New York 46 yard line. Denver was limited to only two net yards on 10 offensive plays in the third period. Simms set Super Bowl records for most consecutive completions (10) and highest completion percentage (88 percent on 22 completions in 25 attempts). He also passed for 268 yards and three touchdowns and was named the game's most valuable player. New York running back Joe Morris was the game's leading rusher with 20 carries for 67 yards. Denver wide receiver Vance Johnson led all receivers with five catches for 121 yards. The National Football Conference (NFC) champion New York Giants captured their first National Football League (NFL) title since 1956 when they downed the American Football Conference (AFC) champion Denver Broncos 39-20 in Super Bowl XXI at the Rose Bowl in Pasadena, California.

The victory marked the National Football Conference's (NFC) fifth National Football League (NFL) title in the past six seasons. The game, played in Pasadena's Rose Bowl, drew a sellout crowd of 101,063. According to A.C. Nielsen figures, the CBS broadcast of the game was viewed in the U.S. on television by 122.64-million people, making the telecast the second most-watched television show of all-time behind Super Bowl XX. The game was watched live or on tape in 55 foreign countries and NBC Radio's broadcast of the game was heard by a record 10.1 million people. New York Giants quarterback Phil Simms was named the Super Bowl Most Valuable Player (MVP) completing 22 of 25 passes for 268 yards and three touchdowns.