The Steelers and Ravens had another classic AFC North collision in Week 9. (Don Wright/Associated Press)

PITTSBURGH—With one dramatic drive engineered by quarterback Joe Flacco late Sunday night at Heinz Field, the Baltimore Ravens kept football’s most rugged division from having a clear-cut front-runner and left open the question of which team is the AFC’s best.

The Pittsburgh Steelers seemed on their way to avenging a four-touchdown loss in Baltimore in the opening game of the season and establishing themselves as the team to beat in the entire conference. They led the Ravens by four points and had Flacco and Baltimore pinned back at their 8-yard line. All that remained was for the Steelers to apply the defensive finishing touches to a triumph that likely would have fueled further speculation about a Super Bowl rematch with the unbeaten Green Bay Packers.

But then Flacco took over, shrugging off a couple of dropped passes to take the Ravens 92 yards, a drive that culminated with a 26-yard touchdown throw to rookie wide receiver Torrey Smith with eight seconds remaining. That gave the Ravens a 23-20 victory and a two-game sweep of the regular season series with the Steelers, and scrambled the AFC North and conference races.

“In my eyes, they are still the defending AFC champs,” Ravens linebacker Terrell Suggs said after the game. “They’re still the team to beat. [But] if we play Ravens football throughout, when we see them again it’ll be in our house.”

Another Steelers-Ravens meeting is far from decided. The Ravens and Cincinnati Bengals are tied for first place in the AFC North, with identical 6-2 records. They’re a half-game in front of the Steelers, who are 6-3. It is the NFL’s only division with three teams that have six wins or more.

The Bengals have been a bit of a surprise, thriving even after quarterback Carson Palmer refused to play for them this season and eventually was traded to the Oakland Raiders. Rookie quarterback Andy Dalton, a second-round draft pick in April, has been steady, enabling the Bengals to back off their vow that they wouldn’t trade Palmer.

The next two weekends could be telling for the Bengals, who host the Steelers next Sunday and play at Baltimore on Nov. 20.

For now, at least, the Ravens can feel like the closest thing there is to a favorite in the division, thanks to their two victories over the Steelers. They won, 35-7, on opening day and prevailed Sunday night in what was, for much of the evening, a typical defense-first renewal of perhaps the sport’s fiercest rivalry.

“If you think about it, this is the only team in the world that’s capable of playing like we play and can match us blow for blow just like they did tonight…. We got the stops when we needed the stops and our offense came through and got one for us,” Suggs said after the game.

The Ravens led, 9-6, after a field goal duel in the first half. They took a 16-6 advantage into the fourth quarter after a touchdown run by tailback Ray Rice. The Steelers grabbed the lead with a rushing touchdown by tailback Rashard Mendenhall and a signature play by quarterback Ben Roethlisberger, who bought time with an improvisational scramble and threw a touchdown pass to wide receiver Mike Wallace.

The Steelers gave the Ravens a bit of an opening when a delay-of-game penalty prevented them from trying a 47-yard field goal with about 2-1/2 minutes to play, keeping their lead at only four points. Still, it seemed to work out fine for the Steelers when their punt left the Ravens with almost the entire field to cover.

“We have a great defense and we’ve always counted on them to make the play,” Roethlisberger said. “We were on the sideline knowing that they were going to do it because they are that good.”

But on this night, it was Flacco who was that good. He took the Ravens down the field and threw what could have been a winning touchdown pass to Smith, who had the ball bounce off his fingertips for an incompletion. Flacco zipped another on-target pass to wide receiver Anquan Boldin a few plays later, only to have the ball carom off his hands for another incompletion. Again, Flacco shrugged it off, and then connected with Smith for the game-winner.

Suggs was asked about his feeling as the Baltimore offense took the field for the decisive drive.

“I was like either one of two things is going to happen: Either we’re going to be the same team as last year, or we’re going to show the world we’ve grown up,” Suggs said.

The Steelers remain formidable, with a proven winner at quarterback in Roethlisberger and a defense still capable of summoning great performances. Pittsburgh played Sunday night without linebackers LaMarr Woodley and James Farrior. Fellow linebacker James Harrison returned from a four-game absence caused by a fractured orbital bone and had three sacks, including one on which he forced a fourth-quarter fumble by Flacco.

But when the Ravens are playing their best, they are among the most balanced teams in the league. They rank second in the league in total defense and scoring defense. They’re seventh in the league in scoring offense. They can run the ball with Rice. And if Flacco can continue to make the big throws when it matters as he did Sunday night, the Ravens are likely to remain prominent in the conversation about which AFC team has the most realistic Super Bowl hopes.

“This Steelers-Ravens game is a game for men,” Ravens Coach John Harbaugh said. “It’s a game for big men. You’ve got to shine bright in the stadium if you want to win this game. Nobody shined brighter than Joe Flacco in this game.”