The Bears' Achilles' heel from last season tripped them up again in Sunday's opener.
The run defense, which allowed a franchise-record 2,583 yards last season, permitted 193 yards on 33 carries in a 23-20 overtime loss to the Buffalo Bills at Soldier Field.
"We didn't play disciplined football," said defensive lineman Lamarr Houston. "When you play good run teams, you've got to play disciplined football."
Fred Jackson rushed for 61 yards on seven carries, including a 38-yarder to the Bears' 1-yard line that set up Dan Carpenter's 27-yard game-winning field goal in overtime.
Anthony Dixon added 60 yards on five carries, including a 47-yarder, while C.J. Spiller gained 53 yards on 15 attempts for the Bills, who ranked second in the NFL in rushing offense last year.
Big play: Chris Conte missed the Bears' entire offseason program while recovering from shoulder surgery and was limited to one preseason game due to a concussion. But that didn't stop the fourth-year safety from making an impact play in Sunday's loss.
With the Bears trailing 17-10 midway through the third quarter, Conte intercepted an E.J. Manuel pass on third-and-two, returning it five yards to the Chicago 44. Five plays later, Jay Cutler threw an 11-yard touchdown pass to Brandon Marshall to tie the game 17-17.
"It was a good play on his part," cornerback Kyle Fuller said of Conte. "He's got great instincts. He was just using what God gave him and came up with the pick."
Conte started at free safety and played most of the game, though Danny McCray came in to spell him for a couple series. Conte's interception was the Bears' only takeaway.
"Chris was playing well," said coach Marc Trestman. "Danny is heavily involved in special teams. We got Chris a lot of playing time today and there were a lot of good things there. Obviously he came up with the interception. He also had a couple of opportunities deep where he just missed on making some plays."
Statistically speaking: Kyle Long led the Bears in rushing with 82 yards on 14 carries and in receiving with eight catches for 87 yards. Marshall had eight receptions for 71 yards, while tight end Martellus Bennett caught eight passes for 70 yards. Alshon Jeffery had five receptions for 71 yards, including a 44-yarder before exiting with a hamstring injury.
Senorise Perry returned one kickoff for 21 yards; five other kickoffs went for touchbacks. Santonio Holmes was dropped for a one-yard loss on the Bears' only punt return of the game and also caught two passes for 21 yards.
Safety Ryan Mundy led the Bears with seven tackles. Defensive end Willie Young recorded Chicago's only sack and also dropped Jackson for a five-yard loss.
News & notes: Before Sunday's loss, the Bears had won all five meetings with the Bills in Chicago, beginning with a 31-13 victory in 1970 at Wrigley Field. … After winning four straight season openers, the Bears fell to 0-1 for the first time since 2009 when they lost to the Packers 21-15 in Green Bay. … The Bears' last season opener that went into overtime was in 1980 when they lost to the Packers 12-6 in Green Bay when kicker Chester Marcol scooped up his blocked field goal attempt and dashed 25 yards for a touchdown. … Sunday's game marked just the fourth time since 2005 that the Bears entered the fourth quarter in a tie. They are now 2-2 in those contests.