The Ravens, NFL champions in 2000, advance to the AFC championship, where they will face the winner of Sunday's game between San Diego and Pittsburgh for a place in the Super Bowl.
The Titans, who won their opening 13 games of the regular season, paid the price for a string of errors including three turnovers and 12 penalties.
Tennessee took the lead in the first quarter through Chris Johnson, who ran eight yards for a touchdown but suffered an injury in the process and was unable to return to action.
The absence of their key running back was a major blow to the Titans, who were unable to penetrate offensively despite dominating in several areas.
The Ravens fought back before the end of the first with Derrick Mason collecting on a superb 48-yard pass from rookie quarterback Joe Flacco.
In a bruising encounter dominated by aggressive defenses, there was no addition to the scoring in the second and third quarters.
It was always likely to be field goals that determined the game in the final period and the Ravens edged in front through a 21-yard effort from the dependable Stover.
Secure Win
The Titans drew level with three points from Rob Bironas but when Flacco found Mark Clayton with an eight-yard pass on a third down, the ice-cool Stover entered to convert from 43 yards and secure the win.
"We are glad to be where we are -- we have two games on our mind now," Flacco told reporters.
"We have a great team around us, we are confident in what we are doing and ready to go out next week against whoever we have to play," he added.
The Ravens' run to the championship game is even more impressive given that, as well as a rookie quarterback, their coach John Harbaugh is in his first year.
Harbaugh said his team, who beat Miami in the wildcard round last week, were getting the basics right.
"Out offense is not turning the ball over and the defense -- to turn the ball over so often, that's a lot of hard hits," he said, adding that the Titans had been tough opponents.
"They are a bunch of strong competitive warriors -- it was a knockdown drag out battle, we are very proud to have a victory against such a good football team," he said.
Titans quarterback Kerry Collins, who stepped up from his number two role after the opening game of the season and guided Tennessee through their impressive regular season, said the team were shattered by the defeat.
"The guys are angry, disappointed, a little bit shocked. For most of the game we played well -- moved it well, the defense played well and that makes it hard to swallow but we have no-one to blame but ourselves," he said.
"We paid for missed opportunities -- we had them and we didn't take advantage of them as we needed to," he said.
