"I don't know why people keep doubting him," wide receiver Anquan Boldin said.
Flacco has won more road playoff games than any quarterback in NFL history, and all have come under Ravens coach John Harbaugh. When the Ravens face the San Francisco 49ers on Feb. 3 in New Orleans, Harbaugh, a former Eagles assistant, will face his brother Jim, the 49ers coach.
The Ravens earned the upset by keeping the Patriots scoreless in the second half, when Flacco threw all three of his touchdown passes. Flacco finished 21 of 36 for 240 yards. The Ravens' leading rusher was rookie Bernard Pierce, a Temple product who had 52 yards on nine carries.
Even if the team had been confident in Flacco before, Sunday's win was further validation of his status among NFL quarterbacks. The blemish on his playoff record had been two losses in the AFC championship game.
Not anymore. His path to the Super Bowl included wins over teams quarterbacked by Andrew Luck, Peyton Manning, and Brady.
"All those guys are great players," Harbaugh said. "But Joe's a great quarterback. He's not just proven that this year. He's proven that for five years."
Flacco reached the AFC title game as a rookie but threw three interceptions in a loss. He made it back last season and almost led the Ravens on a game-winning drive, falling short in a 306-yard, two-touchdown performance.
"We've put ourselves in position to win these games a lot," Flacco said. "Eventually, we were going to push through. It's kind of crazy. This is my fifth year here, this is third game we've played in, and the first game we've won."
When the Ravens punted on their first three possessions Sunday, Flacco remained calm. On the game's fourth drive, he led the Ravens 90 yards while completing 5 of 6 passes before Ray Rice ran for a 2-yard touchdown.
In the second half, the Ravens relied on Flacco to ignite a comeback. He fired his first touchdown pass in the third quarter as Baltimore took a 14-13 lead. On that drive, with the Ravens in a no-huddle offense, Flacco completed 6 of 9 passes, including a 5-yard TD strike to tight end Dennis Pitta.
That up-tempo style continued into the fourth quarter, when Flacco twice found Boldin for scores.
"We didn't come all the way here to play it safe," Flacco said. "We came here for the AFC championship game to play to win."
Flacco's place among the NFL's quarterbacks will remain a popular story line for the next two weeks leading to his first Super Bowl appearance. Another win would continue to validate what was apparent Sunday - that he is among the league's elite.
Contact Zach Berman at firstname.lastname@example.org. Follow on Twitter @ZBerm.