Roethlisberger tried to engineer another comeback for the Steelers, but Michael Griffin came up with his second interception of the day, returning it 83 yards for a touchdown with 16 seconds left.
"It sets the tone for the playoffs in the AFC," Titans linebacker Keith Bulluck said.
In Nashville, Tenn., the Titans (13-2), who came into the game with the third-best defense in the AFC, forced Pittsburgh (11-4) into four turnovers that they turned into 21 points. When it was over, Bulluck celebrated by stomping on a Terrible Towel.
In Sunday's other NFL games, it was: New Orleans 42, Detroit 7; Atlanta 24, Minnesota 17; Buffalo 30, Denver 23; San Diego 41, Tampa Bay 24; Miami 38, Kansas City 31; New England 47, Arizona 7; Seattle 13, N.Y. Jets 3; San Francisco 17, St. Louis 16; Washington 10, Philadelphia 3; Cincinnati 14, Cleveland 0; and Oakland 27, Houston 16.
Atlanta also clinched a playoff spot, but if the Falcons (10-5) are going to make it to the Super Bowl, they may have to beat one or both of the teams that needed overtime to settle the NFC's top seed.
In East Rutherford, N.J., the Giants (12-3) fell behind 28-20 in the fourth quarter, but Eli Manning led a tying touchdown drive with 3:21 left, tossing a slant to Domenik Hixon for the tying 2-point conversion after Brandon Jacobs barreled into the end zone from a yard out.
"Disappointing would be putting it mildly," Panthers quarterback Jake Delhomme said. "The road to the Super Bowl goes through New York. We had a chance. We didn't get it done."
Jacobs powered into the end zone again in overtime, winning the game with 9:57 left. Derrick Ward ran for a career-high 215 yards kept the Giants in the game on a cold, blustery night.
The loss spoiled a record-tying, four-touchdown performance by Panthers running back DeAngelo Williams, who put Carolina up with a 30-yard TD run 2 minutes into the final quarter. He also scored on runs of 13, 5 and 1 yards.
"The only message we sent tonight is that team is getting that swagger back that we had last year at the end of the season," linebacker Antonio Pierce said. "They're going to fight for 60 minutes, overtime, cold weather, being down. To keep fighting, that's what I'm most proud of."
Saints 42, Lions 7
Drew Brees threw for 351 yards and two touchdowns after four Saints ran for scores in the first half. Brees stayed in the game with a 35-point lead late in the fourth quarter to move closer to Dan Marino's single-season record for yards passing. He needs 402 at home against Carolina to break Marino's record of 5,084 set in 1984.
Falcons 24, Vikings 17
Michael Turner rushed for 70 yards and a touchdown for the Falcons (10-5), who were 4-12 a year ago and ended the season without a head coach or a franchise quarterback.
Tarvaris Jackson played very well in his second straight start for the Vikings (9-6), who could have clinched their first division title since 2000. He threw for 233 yards and two scores and rushed for 76 yards, but also had a fumble at the Atlanta 16.
Bills 30, Broncos 23
At Denver, the Broncos blew an early 13-0 lead and set up an all-or-nothing matchup against the Chargers next week for the division title.
The Broncos (8-7) led the Chargers (7-8) by three games with three to go.
Broncos quarterback Jay Cutler threw for 359 yards and broke Jake Plummer's franchise record with 4,210 yards for the season. But an interception at the goal line with less than six minutes left ended Denver's chances.
Chargers 41, Buccaneers 24
After their third straight win in what amounted to elimination games for a team that began the season with high expectations, San Diego (7-8) got the help it needed when Buffalo beat Denver.
Tampa Bay (9-6), which lost its first home game and has dropped three straight, could have clinched at least an NFC wild-card spot with a win and some outside help.
Dolphins 38, Chiefs 31
With their fourth victory in a row and eighth in nine games, the Dolphins (10-5) can clinch the AFC East next week with a win over the Jets just one year after finishing 1-15.
The temperature at kickoff was 10 degrees, with a wind chill of minus-12. Previously, the coldest game the Dolphins ever played was 14 degrees at Foxboro, Mass., on Dec. 11, 1977.
The Chiefs (2-13) concluded the home portion of what's certain to be the worst season in the 49-year history of the franchise. They were 1-7 at Arrowhead.
Patriots 47, Cardinals 7
At Foxborough, Mass., the Patriots pressured Kurt Warner into one of his worst games in 11 pro seasons as he threw for just 30 yards.
The Cardinals' (8-7) defense allowed the Patriots (10-5) to score on nine of their 10 possessions before Matt Cassel got the rest of the game off.
The Patriots could win the division and earn the No. 3 seed in the conference if they win and the Jets beat or tie Miami.
Seahawks 13, Jets 3
At Seattle, Maurice Morris sliced through the snow for a season-high 116 yards and John Carlson scored the only touchdown on a short pass from backup Seneca Wallace as the Seahawks (4-11) ended the Jets' stay atop the AFC East.
Mike Holmgren, Brett Favre's confidant and former coach in Green Bay, went out a winner in his final home game as the leader in Seattle - largely because Favre came up short when the Jets (9-6) needed him most.
Redskins 10, Eagles 3
At Landover, Md., the Redskins made a stop at the 1-yard line on the game's final play.
As Reggie Brown caught the ball near the goal line, cornerback Fred Smoot lifted him into the air, and safety LaRon Landry supplied the shove that kept the Eagles receiver out of the end zone. With no timeouts remaining, Philadelphia (8-6-1) couldn't stop the clock.
Clinton Portis scored his first touchdown in eight weeks in a win that offered the Redskins (8-7) a consolation prize on the day they were mathematically eliminated from the postseason.
49ers 17, Rams 16
Bruce became the fifth player to reach 1,000 catches on a 3-yard touchdown grab with 4:12 to go and passed Tim Brown for second on the career yards receiving list on the 49ers' go-ahead drive.
The Rams (2-13) squandered a 10-point lead for the second straight week, failing to capitalize on four turnovers and four sacks while losing their ninth in a row.
At Cleveland, Cedric Benson rushed for a career-high 171 yards and Leon Hall returned one of his three interceptions 50 yards for a touchdown to help the Bengals get their first road win this season with a victory over the hapless Browns.
After losing their first eight games, the Bengals (3-11-1) have won two in a row for the first time since the final two games of 2007.
Cleveland (4-11) has lost five straight, seven of eight and hasn't scored an offensive TD since running back Jerome Harrison's 73-yard sprint on Nov. 17 at Buffalo - nearly 21 quarters ago.
Raiders 27, Texans 17
The Texans (7-8) had won four straight for the first time in team history and were hoping for their first winning season. But Houston could generate little against the Raiders (4-11).
But by beating the Texans for the first time in four tries, the Raiders are assured of not tying Tampa Bay for the most losses in any six-year period. Oakland is 23-72 since the beginning of the 2003 season.