LONDON -- Who was Dat?!

The New Orleans Saints defense, which allowed more than 1,000 yards and 65 points in the first two weeks, delivered perhaps the most unlikely shutout of the 2017 season -- a 20-0 trouncing of the Miami Dolphins in London on Sunday.

In the process, the 2-2 Saints have completely rebooted their season heading into the Week 5 bye.

The Saints limited Jay Ajayi and the Dolphins to just 186 yards of offense on Sunday. Henry Browne/Getty Images

New Orleans' defense followed up its surprising 34-13 rout at the Carolina Panthers last week with an even more emphatic performance, holding Miami to zero points and just 186 yards.

Saints cornerback Ken Crawley, who was a healthy inactive for the first two weeks this season, intercepted his first career pass in the end zone on Miami's opening drive. The Dolphins never crossed New Orleans' 40-yard line again after that. The Saints also sacked Dolphins quarterback Jay Cutler four times.

"Look, they're all important games," Saints coach Sean Payton said. "(But) certainly to be at this position, starting off the way we did, is encouraging.

"It was a good one to get. A long way to come get it -- but it was worth it."

What it means: The Saints' revitalized defense will truly be tested in the next two games (versus the Detroit Lions in Week 6, then at the Green Bay Packers in Week 7). But they have officially gotten their mojo -- and their season -- back after a brutal start. Payton always likes to quote his mentor, Bill Parcells, who says confidence is born of demonstrated ability. Now this young defense's confidence should only grow.

"I feel like the last game, that shutout, it was expected," said Crawley, a second-year pro who went undrafted last year. "That was our goal through camp. I feel like guys came together. We know what kind of defense we want to be. We always hear about other defenses around the league. We want to be that. We’re a young group. I feel like it’s giving us momentum. I feel like we’re going to go somewhere with this type of defense."

Historic ball security: The Saints became just the third team since 1933 to start the season without a turnover in their first four games, according to the Elias Sports Bureau. The others are the 1995 Rams and 2013 Titans.

What I liked: Michael Thomas: Sure, he dropped two passes to go with some other sloppiness on the Saints' offense. But when the Saints absolutely needed a big play, Thomas delivered time and time again. He finished with eight catches for 89 yards and at least two clutch third-and-long conversions.

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What I didn't like: Dropped balls: I didn't get an official count, but Thomas and running back Mark Ingram dropped at least two passes each. And there was one sloppy series of events where the shotgun snap sailed over Drew Brees' head; Ingram and receiver Tommylee Lewis both failed to recover it before Brees finally landed on it. The Saints' offense seemed sluggish and out of sync for most of the first half on a cool overcast day in London, with some slipping on the unfamiliar grass surface. They didn't score any points until a field goal as time expired in the first half.

Fantasy fallout: Peterson disappearing: Adrian Peterson's role has only continued to shrink as the season has continued. He had just four carries for a total of 4 yards. And when the Saints were protecting a lead late, it was rookie Alvin Kamara who got the call on a 12-yard touchdown pass from Brees. Ingram remains the lead horse in this timeshare (he had 14 carries for 45 yards and four catches for 17 yards). And Kamara remains the one with the most upside (five carries for 25 yards; 10 catches for 71 yards and a TD). Peterson is all but removed from the picture, barring injury.

Strief hurt again: Saints right tackle Zach Strief left the field with a knee injury again in the second half after he just returned this week from a sprained MCL. Strief was able to walk off under his own power after appearing to be in pain on the field. But he ultimately rode back to the locker room on a cart after being evaluated. The good news is that if Strief is sidelined beyond the Week 5 bye, left tackle Terron Armstead should be ready to return from a shoulder injury. ... Rookie linebacker Alex Anzalone (shoulder) and tight end Josh Hill (concussion) also left the game early and did not return.

What's next: A bye in Week 5, followed by the dates with Matthew Stafford and Aaron Rodgers.