PITTSBURGH, Pennsylvania (AFP) - Lamarr Woodley and Keyaron Fox returned Brett Favre turnovers for late touchdowns Sunday and Pittsburgh beat previously undefeated Minnesota 27-17 in a National Football League game.

The reigning Super Bowl champions had not scored two defensive touchdowns in the same quarter since 1995 but the Steelers shut down late Vikings marches by forcing mistakes from veteran Favre to stifle Minnesota threats.

One of two other NFL unbeatens in action Sunday stayed perfect. Indianapolis improved to 6-0 with a 42-6 rout at winless St. Louis as Peyton Manning threw three touchdown passes. New Orleans (6-0) was to play at Miami later.

Pittsburgh improved to 5-2 with a fifth consecutive triumph with some help from fourth quarter blunders by the once-perfect Vikings.

A tripping penalty on Minnesota blocker Jeff Dugan wiped out a touchdown for the Vikings and just two plays later, Steelers defensive end Brett Keisel knocked the ball from Favre's grasp.

Woodley grabbed the fumble and raced 77 yards for a touchdown, teammates blocking out tackle attempts on the runback to give Pittsburgh a 20-10 lead with 6:42 to play.

Minnesota's Percy Harvin answered on the ensuing kickoff with an 88-yard touchdown return that pulled the Vikings back within 20-17 with 6:23 to play before Favre marched Minnesota downfield oncve again in the final seconds.

A deflected Favre pass wound up in the hands of Steeler defender Fox, who raced 82 yards with the interception for a touchdown that gave Pittsburgh a 27-17 lead with 83 seconds remaining, ending the Vikings' hopes.

It was only the third interception surrendered by Favre in seven games.

An offensive pass interference penalty on Pittsburgh's Heath Miller erased a first-quarter touchdown as the Steelers settled for a 39-yard Jeff Reed field goal to open the scoring.

Minnesota seized a 7-3 lead on Adrian Peterson's two-yard touchdown run with 5:12 remaining in the second quarter, the 13-play march equaling their longest of the season.

Favre was 5-of-9 for 60 yards in the drive for Peterson's eighth rushing touchdown of the seasson, which matched the NFL lead.

Ben Roethlisberger answered with a 40-yard touchdown pass over the middle of the field to rookie Mike Wallace with 24 seconds remaining in the second quarter to give the Steelers a 10-7 half-time lead.

"Big Ben" marched the Steelers 91 yards in 75 seconds for the go-ahead score.

Reed kicked a 27-yard field goal 3:55 into the second half to give the Steelers a 13-7 lead but Ryan Longwell answered from 18 yards just 6:21 later to pull the Vikings back within three points.

At St. Louis, Manning threw touchdown tosses of 27 yards to Dallas Clark and six yards to Reggie Wayne in the first quarter and another of eight yards to Austin Collie with 3:42 remaining.

Joseph Addai scored on a six-yard touchdown run in the second quarter, Jacob Lacey returned an interception 35 yards for a touchdown late in the third and Chad Simpson ran 31 yards for another touchdown to complete the rout.