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The Minnesota Vikings were once bruised, battered and 0-1, the victim of a harsh beating at the hands of the more physical San Francisco 49ers in Week 1.

The bullied has suddenly become the bully.

The now 2-1 Vikings have won back-to-back games, in large part due to the savage pummelings provided to quarterbacks Matthew Stafford and Philip Rivers by the Minnesota defense.

The San Diego Chargers were all but forced to wave the white flag in the fourth quarter of Sunday's 31-14 loss in Minnesota. Down big and with Rivers getting hit on every dropback, the Chargers played the safe card and pulled the veteran quarterback.

A week earlier, Stafford limped to the sidelines in visible pain after nearly every possession against the Vikings defense.

The last two weeks have provided a stern warning to offenses on the Vikings schedule: either protect your quarterback, or Minnesota is going to put a serious hurting on your franchise signal-caller.

Mike Zimmer's attacking defense put Rivers under siege on Sunday.

Using a variety of A-gap blitzes, the Vikings made the typically unflappable Rivers look shaky and startled in the pocket. The league's leader in completion percentage coming into the week, Rivers completed just 21 of 34 passes for 246 yards and one touchdown. He took four sacks, including one resulting in a lost fumble. His lone interception was returned 92 yards by linebacker Chad Greenway for a score.

Zimmer's plan for containing Rivers—as told to Tom Pelissero of USA Today—played out perfectly:

The official box score credited the Vikings with just two quarterback hits, but emerging linebacker Anthony Barr put at least a half-dozen thumps on Rivers Sunday. San Diego's offensive line—which was devastated by injury—had no answer for Zimmer's signature blitz, which featured Barr and rookie Eric Kendricks crashing the interior of the line to the right and left of the center.

Rivers nearly the left the game early in the second half after Barr delivered a vicious hit to the ribcage of the Chargers quarterback. With Rivers struggling to deal with the aftershocks of the hit, the Chargers were forced to call timeout to keep him in the game.

He didn't last long. With the Vikings up 31-7 in the fourth quarter, Everson Griffen and Sharrif Floyd combined to sack a visibly frustrated Rivers on fourth down. Head coach Mike McCoy put in veteran Kellen Clemens to start San Diego's next series.

Stafford knows Rivers' pain.

According to Pro Football Focus, the Lions quarterback was under pressure on 23 of his 58 dropbacks against the Vikings in Week 2. Despite sacking Stafford just once, the Vikings defense hit him nine times and hurried him on another 16 occasions.

The beating resulted in doubts of whether Stafford would play in Week 3 against the Denver Broncos. He required X-rays on his chest after the contest, per Tim Twentyman of the Lions' official site.

The role of aggressor is a good look for the Vikings, especially when viewed in the shadow of Week 1. The 49ers repeatedly punched Minnesota's defense in the opener, using a power run game to overwhelm Zimmer's front four. As a result, 49ers quarterback Colin Kaepernick was largely untouched as he played a supporting role.

The tides have turned the last two weeks.

Jim Mone/Associated Press

The Lions and Chargers combined to rush for just 128 yards. No rusher from either team cracked 60 yards, a stark contrast to the 168 allowed to running back Carlos Hyde in the opener.

By consistently stopping the run, the Vikings have allowed their dominant front four and creative blitz packages to terrorize quarterbacks.

Griffen has three sacks over the last two games, and Barr and Kendricks—the promising pair of UCLA linebackers—have come alive as Zimmer's go-to blitzers.

No quarterback will want to play this current version of the Vikings defense.

With a suffocating and attacking group now laying waste to quarterbacks, Minnesota has made Week 1's disaster a distant memory. Now the bully, the Vikings have stuffed both Rivers and Stafford into lockers the past two weeks. Up next: Peyton Manning.

Zach Kruse covers the Vikings for Bleacher Report.

Follow @zachkruse2