Ray Lewis and the Baltimore Ravens got there with a hard-hitting defense that made it a major challenge for opponents to move the ball.
On Sunday, one of those teams will advance to the Super Bowl because, most likely, of what they do best.
"We've got our hands full this week," Lewis said. "You watched what they did last week against Denver, just the way they came out and ran their offense, how efficient (Brady) was, how many different receivers he hit with the ball. I think their offense, period, is playing at a very high level."
From start to finish, Brady picked apart the Denver defense in a 45-10 divisional playoff win.
"You don't want him back there just like, `Oh, we're just going to play catch today,"' Baltimore linebacker Terrell Suggs said. "You don't want him to zone in, get in his zone, so to say. So I think pressure is going to be crucial, but it's always crucial. But, particularly when you are playing these type of quarterbacks, it's pivotal."
The Patriots, with Welker and Gronkowski doing most of the damage, were second in the NFL with 428 yards per game and third with an average of 32.1 points.
"They're great players. I've played against both those guys quite a few times," Brady said. "You always enjoy going up against the best because you can really measure where you're at. You can't take plays off against those guys. You can't take things for granted when you're out there against them. You have to see where they're at on every play because they're guys who change the game."
And don't forget Suggs. He led the AFC with 14 sacks, and, with Lewis and Reed were picked as Pro Bowl starters this season.
The Ravens have a "very attacking type defense," Welker said. "They're very physical. They run to the football really well. They rush well, cover well, tackle well across the board. They have a lot of great players and a lot of playmakers."
But they haven't faced a passing attack with the weapons the Patriots have. Welker led the NFL with 122 catches and 1,569 yards receiving. Gronkowski was fifth with 90 catches and set an NFL record of 17 touchdown catches by a tight end. And Aaron Hernandez, a tight end who often lines up at wide receiver and had a 43-yard run out of the backfield against Denver, was 14th with 79 receptions.
"That's why communication in these games is so vital and not going crazy and overthinking things - just getting lined up and playing - because you can get anything. You don't know what you're going to get."
The last playoff game between the teams two years ago was a huge surprise with the Ravens offense dominating.
"We don't really care too much about what's happened in the past. We've won some, we've lost some, but right now this team is focused with the Ravens," Patriots coach Bill Belichick said. "That's really all that matters. I don't think some game that happened two years ago or five years ago or anything else, I don't think that really has an effect on this game."
The home crowd could have a big effect.
"Anytime you go into a road playoff game, you know it is going to present its challenges in dealing with the crowd noise and things like that," Baltimore quarterback Joe Flacco said. "We play a lot of good teams that have great crowds. It definitely prepares us for something like this.
"You can let that have a positive effect for the home team. I think you have to do something mentally that was not very sharp in order to let that be a factor."
There will be much bigger factors that determine the outcome of the game.
"When you do watch how the games are played, nine times out of 10, I just truly believe defense is going to find a way to win the championship," Lewis said. "You can go back however many years you want to go back, and defenses have a way to come out to make a play that changes the outcome of games."
Unless, of course, you're facing Brady.
"I try to be the best I can be every week," he said. "I don't think long-term too often, especially in weeks like this."