Emmitt Smith earned MVP honors after rushing for 132 yards and two TDs. (AP)
Emmitt Smith rushed for 132 yards and two second-half touchdowns to power the Cowboys to their second consecutive NFL title.
By winning, Dallas joined San Francisco and Pittsburgh as the only franchises with four Super Bowl victories. The Bills, meanwhile, extended a dubious string by losing in the Super Bowl for the fourth consecutive year.
To win, the Cowboys had to rally from a 13-6 halftime deficit. Buffalo had forged its lead on Thurman Thomas's 4-yard touchdown run and a pair of field goals by Steve Christie, including a 54-yard kick, the longest in Super Bowl history.
But just 55 seconds into the second half, Thomas was stripped of the ball by Dallas defensive tackle Leon Lett. Safety James Washington recovered and weaved his way 46 yards for a touchdown to tie the game at 13-13. After forcing the Bills to punt, the Cowboys began their next possession on their 36-yard line and Smith, the game's most valuable player, took over.
He carried seven times for 61 yards on the ensuing 8-play, 64-yard drive, capping the march with a 15-yard touchdown run to give Dallas the lead for good with 8:42 remaining in the third quarter.
Early in the fourth quarter, Washington intercepted Jim Kelly's pass and returned it 12 yards to Buffalo's 34. A penalty moved the ball back to the 39, but Smith carried twice for 10 yards and caught a screen pass for nine, and quarterback Troy Aikman completed a 16-yard pass to Alvin Harper to give the Cowboys a first-and-goal at the 6.
Smith took it from there, cracking the end zone on fourth-and-goal from the 1 to put Dallas ahead 27-13 with 9:50 remaining. Eddie Murray's third field goal, from 20 yards with 2:50 left, ended any doubt about the game's outcome.
Smith had 30 carries in all, with 19 of his attempts and 92 yards coming after intermission. Washington, normally a reserve who played most of the game because the Cowboys used five defensive backs to combat the Bills' No-Huddle offense, had 11 tackles and forced another fumble by Thomas in the first quarter.
Aikman completed 19 of 27 passes for 207 yards. Buffalo's Kelly completed a Super Bowl-record 31 passes in 50 attempts for 260 yards
Dallas, the first team in NFL history to begin the regular season 0-2 and go on to win the Super Bowl, also became the fifth to win back-to-back titles, following Green Bay, Miami, Pittsburgh (the Steelers did it twice), and San Francisco.
Buffalo became the third team, along with Minnesota and Denver, to lose four Super Bowls.
The Cowboys' victory was the tenth in succession for the NFC over the AFC.