The Pittsburgh Steelers can clinch the AFC North title Sunday. That is, if they can top the Baltimore Ravens in a battle of the top two defenses in the league. The defensive units of these division rivals generate plenty of statistical intrigue for Sunday’s showdown in Baltimore, which qualifies as the NFL Matchup of the Week.

Going into Week 15, the 10-3 Steelers top the NFL in total defense, allowing just 241.9 yards per game. The defense of the 9-4 Ravens is second with a 253.4 yards-per-game average.

The stinginess of the defenses takes on an added dimension Sunday. The Ravens have given up an average of just 10.0 points per game at home, the lowest mark in the league. The Steelers have allowed 11.3 points per game on the road, and only the Titans (10.8) have averaged fewer points allowed per game away from home.

So, look for a defensive battle? Probably, but who knows?

The last time the two teams hooked up, on Sept. 29, Pittsburgh came away with a 23-20 overtime victory on a 46-yard field goal by Jeff Reed. Both clubs allowed 20 or more points. Baltimore has done that in just three games all season; Pittsburgh has given up 20 or more only four times.

The Steelers’ defensive unit hasn’t allowed 300 total yards in a game since the 2007 regular-season finale, when the Ravens secured a 27-21 home victory on Dec. 30. Opponents are averaging just 3.92 yards per play this season against the Pittsburgh defense, which would be the lowest full-season average since the 1979 Buccaneers held the opposition to just 3.89 yards per play. And the Steelers have executed 10 takeaways in their last two games -- in wins over New England and Dallas.

Pittsburgh has won four straight games on the road, as well as its last four overall. Baltimore has won seven of its last eight games and has a 5-1 record at home. The only home loss came at the hands of the 12-1 Titans on Oct. 5.

The Ravens’ defense has allowed just three rushing touchdowns all season. It hasn’t given up one at home in 134 consecutive carries, dating to last year’s season finale against Pittsburgh, when Najeh Davenport ran in from the one in the second quarter of Baltimore’s victory. Playing at home, the Ravens have held their last nine opponents to fewer than 100 rushing yards and haven’t allowed a rush of 15 or more yards since November 2007. No individual has rushed for 100+ yards at the Ravens’ house in 24 straight games.

Baltimore faces a Pittsburgh offense that hasn’t looked championship caliber for most of the season. Quarterback Ben Roethlisberger isn’t having one of his better years, and the Steelers’ running game has failed to rush for more than 70 yards in five games. The team’s 103.8 rushing yards per game ranks 23rd in the NFL, and it has the league’s worst third-down conversion rate. The defense has kept the Steelers in games, and has allowed the offense plenty of possession time to get on track.

Although the Ravens’ offense has often sputtered as well, in those seven wins over the last eight weeks, Baltimore has averaged 32.6 points per game. OK, the defense has played a key role in scoring: Terrell Suggs has a pair of long interception returns for scores, Ed Reed ran one fumble back for a touchdown and set an NFL record with a 107-yard TD return of an interception on Nov. 23 against Philadelphia. He has a pair of interceptions in two of Baltimore's last three games.

Still, Baltimore has dominated time of possession during its recent surge. For the season, the offense has had 24 possessions of five minutes or more, tied for third most in the league. The Ravens have been a running offense, rushing on an NFL-high 56.5 percent of their offensive snaps.

The running game hasn’t been a resounding success for the Ravens, as both they and the Steelers rank near the bottom of the league in yards per rush. By grinding it out on the ground, though, the Ravens are the only NFL team that has four backs with at least 450 rushing yards this season -- Le’Ron McClain, Willis McGahee and Ray Rice -- a feat only the 2003 Eagles and 2004 Chiefs have matched in the last 10 years.

For the Ravens, a key difference of late has been quarterback Joe Flacco. The 23-year-old rookie, who has a 60.2-percent completion rate that’s not far off Roethlisberger’s NFL rookie record (66.4 percent in 2004), has turned in impressive efforts in five of the last eight games -- though the four best have come on the road. In this stretch, he has thrown 12 TD passes and just three interceptions, good for a 95.6 passer rating.

It’s been premier defensive units, however, that have sparked Super Bowl championships for both clubs since the NFL-AFL merger, and it’s likely that the success of the defenses will be critical to how far the Steelers and Ravens advance in the postseason. Sunday’s game is a playoff primer for both teams, and the AFC North title is still on the line.