Dallas Cowboys – 1998
The Cowboys enjoyed a great period of dominance in the ’90s but that fizzled out at the end of the decade. Nonetheless, analysts projected the 10-6 team to crush the Cardinals in the Wild Card Round. Arizona had never even won a playoff game in its history at this point.

Meanwhile, Dallas smashed the Cardinals twice during the regular season. It appeared to be a foregone conclusion but Arizona belied all expectations. Troy Aikman threw four interceptions while Arizona got him for four sacks. They won the game 20-7 against all odds (via Pro Football History).