ARLINGTON, Texas (AP) -- Cam Newton is still unbeaten this season, while Tony Romo might be out for good with the same injury that sidelined him for seven games.
Newton got a big boost from a defense that returned two of Romo's three interceptions for touchdowns as the Panthers ran their NFL-best winning streak to 15 regular-season games with a 33-14 victory over the Dallas Cowboys on Thursday.
Romo injured the same left collarbone that sidelined him for all seven games of a losing streak that damaged the playoff hopes for the defending NFC East champion Cowboys (3-8).
"You can hear something happen, you're just disappointed, frustrated," Romo said.
Cowboys owner Jerry Jones said the team needs more information to know Romo's status for the rest of the season, and the 35-year-old quarterback will have more tests Friday. Coach Jason Garrett said X-rays taken when Romo came out of the game were inconclusive.
Carolina linebacker Luke Kuechly intercepted two straight passes by Romo, returning the first 32 yards for a touchdown.
Safety Kurt Coleman picked off Romo's second pass of the game and took it back 36 yards for a score to help the Panthers become the 16th NFL team to start a season 11-0.
Chicago's Jay Cutler threw for 200 yards and a score as the Bears held off Green Bay on fourth-and-goal from the 8 with 22 seconds left for a 17-13 win.
Aaron Rodgers' throw to the end zone deflected off receiver Davante Adams' hands on the rain. James Jones couldn't hang on to a potential touchdown catch on third down. Cornerback Tracy Porter intercepted Rodgers' pass with 3:19 left at the Bears 45 on the Packers' previous drive.
The highlight of the night for Green Bay turned out to be the return of Brett Favre, whose name and No. 4 was unveiled at halftime next to the team's other retired numbers.
Chicago (5-6) has won three of its last four. The Packers (7-4) lost a second straight home game.
Jeremy Langford ran for a touchdown for Chicago.
In Detroit, Matthew Stafford equaled a career high with five touchdown passes, three to Calvin Johnson, as the Lions routed the Philadelphia Eagles 45-14 for their third straight victory.
Stafford threw for more than 200 yards and three touchdowns without a turnover in the first half to help the Lions (4-7) take a 24-7 lead. He finished 27 of 38 for 337 yards.
The Eagles (4-7) have lost three straight. They have allowed at least 45 points in two straight games in one season for the first time in team history.
Mark Sanchez started for Philadelphia with Sam Bradford inactive because of a shoulder injury. Sanchez was 19 of 27 for 199 yards and two touchdowns.
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