Big Papi was a major contributor in the Red Sox 2004 World Series run. Any Red Sox fan knows that the World Series run wouldn't have been possible without overcoming a 3-0 series deficit against the Yankees. And Big Papi exhibited his postseason heroics to help the comeback, especially in Games 4 and 5.
We all know about Dave Roberts steal which set up a Bill Mueller RBI to tie the game in the ninth. 'The Steal' could be the biggest play in Red Sox history, as a comeback wouldn't be likely without it.
So the Red Sox stayed alive in the ninth, but still needed another run to schedule a Game 5. Enter David Ortiz. The Red Sox and Yankees stayed tied at 4, until David Ortiz hit a walk-off two run home run in the bottom of the 12th. That gave the Red Sox their first win of the series, and forced a Game 5 later that night.
Fresh off a walk off in Game 4, Ortiz didn't fail to disappoint in Game 5 as well. The Red Sox were looking for more magic to help send the series back to New York for a Game 6. Again, enter David Ortiz.
The game was tied at 4 yet again, but this time in the 14th inning. Ortiz stepped up to bat with 2 outs, and a man on first and second. Ortiz connected a hit a RBI single which scored Johnny Damon and won the Red Sox the game. They sent the ALCS back to New York, and won the next two games in New York. The Red Sox came back from 3-0 series deficit and advanced to the World Series where they swept the Cardinals for their first title in 86 years.
Without clutch hitting from Ortiz, the Sox may have got swept by the Yankees or never have won the 2004 title. Luckily Ortiz came through in the clutch and kept the Red Sox World Series chase alive.