MINNEAPOLIS — The Washington Redskins faded away quietly late Thursday night in a 34-27 loss to the Minnesota Vikings, and any hope they had of salvaging their season may have disappeared as well.

The Redskins looked like a team on the rise as they took a 13-point lead in the third quarter, but their dispirited finish stirred more questions about where they’re headed. The Redskins’ defense collapsed as the Vikings stormed back with 20 unanswered points — including 13 straight after starting quarterback Christian Ponder was knocked out of the game because of a shoulder injury late in the third — and the Redskins came up short again on their final drive.

The Redskins drove from their 20-yard line to the Minnesota 4, but wide receiver Santana Moss couldn’t stay inbounds while catching a pass in the left corner of the end zone from quarterback Robert Griffin III. After taking over on downs, the Vikings ran out the clock for only their second victory in nine games.

The loss could prove to be a major blow to the Redskins (3-6), who despite an 0-3 start still aspire to win the weak NFC East and return to the playoffs. The Redskins lost ground in the division because their defense collapsed and their offense, which rolled for three quarters, stalled. Let’s start there.

Disappearing act

For defensive coordinators, the game plan is simple against the Vikings: Try to stop second-to-none running back Adrian Peterson.

Against Peterson — no other rushers possesses his unique combination of size, speed, vision, power and shiftiness — defensive players must remain disciplined in their run responsibilities. Covering each gap along the line on every play is essential because Peterson exploits mistakes with his cutback ability.

Overall, the Redskins’ run defense was outstanding. They swarmed Peterson, limiting him to only 75 yards and a 3.8-yard average.

Unfortunately for defensive play-caller Jim Haslett, Peterson had two rushing touchdowns, including a one-yarder in the third as the Vikings rallied. At the most inopportune moment for the Redskins, their defense vanished.

In the first half, the defense played effectively — Ponder completed 17 of 21 passes in the game but only had 174 yards — at times as the Redskins built a double-digit lead. Then in the third and fourth quarters, the Redskins failed to pressure the quarterback and experienced breakdowns in pass coverage. That’s called bad timing.

Wasted offense

Griffin, who had 281 yards passing, matched his career high with three touchdown passes in the first half. Running back Alfred Morris (139 yards rushing) had his best game of the season. Again, wide receiver Pierre Garcon (119 yards) was a difference-maker in the passing game. And the offensive line, for three quarters anyway, was sharp at both pass protection and run blocking.

When Morris was in top form last season, he finished runs with such a bruising style that many defensive players backed off of him late in games. On several runs Thursday, Morris steamrolled Vikings players.

Morris generates impressive leg drive and is able to maintain his balance while being corralled by several would-be tacklers. Against the Vikings, Morris extended runs by dragging players after initial hits.