It was, strangely, one of the cleaner games you'll see an NFL team flounder through, at least in terms of penalties and turnovers.

Playing at Chicago, the Vikings had just one penalty, no interceptions and no fumbles. Yet they scored 10 points, mustered 15 yards during a first-half stretch of four consecutive three-and-outs and lost by 10 to a 1-6 Bears team missing five starters.

Yessir, even though the Vikings have the league's stingiest defense (14.9), the margin for error has become infinitesimal as the offensive line's weaknesses have been exposed exponentially in giving up 11 sacks and 22 additional quarterback hits in a two-game losing streak.

The Vikings' current freefall from 5-0 Super Bowl favorites to 5-2 playoff question marks began a week earlier with a false-start penalty on tight end Rhett Ellison on second-and-goal at the Eagles 1-yard line early in the first quarter of a 0-0 game at Lincoln Financial Field. This came two snaps after safety Andrew Sendejo handed the offense the ball at the 2-yard line.

With the Vikings' offensive line in its current state of instability, second-and-goal at the 6 became an insurmountable obstacle. Two snaps later, Sam Bradford was hit as he threw an interception in the end zone. The game changed and the Eagles won 21-10.

Defense, they say, wins championships, as Denver proved again last season. But a look around the league makes you think it sure doesn't hurt to have an offense that can slam down the accelerator and outrace all of its team's mistakes.

Oakland quarterback Derek Carr threw for 513 yards on Sunday, covering up for the team’s 23 penalties.

This came to mind while watching the Vikings sputter for 258 yards despite near perfection in terms of penalties and turnovers on Monday night. A day earlier, the Raiders lost the turnover battle and committed 23 penalties to break an NFL record established 72 years ago.

Yet after the game, when told the Raiders had surpassed — by one penalty — the 1944 Brooklyn Tigers, the 1944 Bears and the 1998 49ers, Oakland quarterback Derek Carr shrugged.

"The refs, I think, did a great job," Carr said.

Say what?

Carr didn't care because in spite of 23 penalties for 200 yards, the Raiders still put up 626 yards of offense and 30 points while beating Tampa Bay to improve to 6-2 overall and 5-0 on the road.

Carr threw for a franchise-record 513 yards. If not for penalties, he would have had another 71 yards and shattered the 65-year-old NFL record of 554 yards passing set by Rams quarterback and former Vikings head coach Norm Van Brocklin.

"The great thing is we played through [the penalties]," Raiders coach and former Vikings linebacker Jack Del Rio said.

You can say that again. The 626 yards were 356 more than the Bucs had, and the most by any NFL team in two years.

The Vikings were able to piece together a 5-0 start with backup Shaun Hill in the opener and Bradford once he got up to speed after arriving via trade eight days before the season began. But injuries, defensive adjustments by the opposition and consecutive road games have left the Vikings needing almost the perfect game in order to compete.

Even the Vikings' lone penalty on Monday night — a holding call on T.J. Clemmings — caused perhaps the most important drive of the night to stall. Clemmings was called for holding four snaps after the Bears opened the second half with an 11-play, 75-yard touchdown drive in which they went 3-for-3 on third down. Two snaps later, the Vikings had to punt while trailing by 17.

Meanwhile, Del Rio's unruly band of Raiders is making a mockery of the notion that penalties are a problem. With 103 penalties at the midway point of the season, the Raiders have 23 more than the second-most-penalized teams, Washington and Jacksonville. Throw out the Raiders, and the other 31 teams are averaging 61.2 total penalties.

Of course, it helps the Raiders that left tackle Donald Penn, left guard Kelechi Osemele, center Rodney Hudson and right guard Gabe Jackson have started every game together this season. Right tackle Austin Howard has started four games, including the past three.

That's the kind of continuity the Vikings haven't seen up front in years. In fact, the last time the Vikings had five offensive linemen start every game together was 2012.

That, of course, was the year they surprised the league by making the playoffs with Christian Ponder at quarterback and Adrian Peterson running for 2,097 yards en route to winning league MVP.

Purple lines matter.

Mark Craig is an NFL and Vikings Insider. • Twitter: @MarkCraigNFL • E-mail: mcraig@startribune.com