The Lions were facing third-and-goal from the Vikings 1 early in the second quarter of Sunday's game at U.S. Bank Stadium.

They swaggered to the line of scrimmage with three tackles, one tight end, a fullback and a future Hall of Fame running back with more rushing touchdowns than all but three players in NFL history.

So what happened?

Defensive tackle Jaleel Johnson destroyed right guard Halapoulivaati Vaitai and slammed into former Vikings superstar Adrian Peterson 4 yards behind the line of scrimmage. Middle linebacker Eric Kendricks joined the scrum and Peterson was dumped at the 5-yard line, denied a 114th career rushing touchdown.

Detroit settled for a 23-yard field goal and trailed 13-3 in a game they lost 34-20.

"I had an idea on the third down that they were going to do that [with Peterson], so we got lucky in some of those areas," Vikings coach Mike Zimmer said. "But that's part of it, and honestly we worked extremely hard on red zone, inside the 5-yard line, and that's part of it.

"Understanding where you're at. Understanding what they like to do. We spend a couple days every week trying to be good at that."

Mission accomplished Sunday.

The Lions reached the Vikings 20-yard line or closer six times. They scored two touchdowns, including a 2-yard "drive" that came with the Vikings leading 34-13 and having just surrendered their second blocked punt of the second half.

The other four trips to the Minnesota 20 ended this way:

• A missed 46-yard field goal after a 9-yard sack on third down was shared by Hercules Mata'afa and Shamar Stephen. The 6-2, 254-pound Mata'afa lined up at left end and drove 6-4, 315-pound right tackle Tyrell Crosby back into the quarterback.

• The 23-yard field goal after the Peterson stop included cornerback Kris Boyd's sideline tackle inches from the goal line on second-and-goal from the 6.

• An interception by linebacker Eric Wilson on first down from the 20. The Lions had driven 45 yards when Wilson got in front of tight end T.J. Hockenson, intercepted the ball at the 12 and returned it 16 yards with the Vikings leading by 17 in the third quarter.

• An interception by Kendricks in the end zone on third-and-goal from the 5. Trying to capitalize on Detroit's first blocked punt, Matthew Stafford went back to Hockenson off a double move but wasn't able to fool the reigning first-team All-Pro middle linebacker.

The Vikings defense has been decimated by injuries. Before that, it was weakened by the offseason departures of its top three corners and half of its starting defensive line. Then COVID-19 caused nose tackle Michael Pierce — the prized free-agent acquisition — to opt out of the season.

The numbers weren't pretty heading into Sunday's game. The Vikings ranked 29th in points allowed (30.6) and yards allowed (411.7).

But …

In red-zone defense, they ranked eighth, with opponents reaching the end zone 57.69% of the time. And on third down, they ranked fifth, with opponents converting 35.37% of the time.

"Down in the red zone," said rookie cornerback Jeff Gladney, "we just buckle up and play our keys and have great eyes."

Those eyes are maturing at the halfway point of the 2020 season.

Included among the guys who made key red-zone plays, Boyd began the year as the team's fifth corner; Johnson became a starter only because Stephen had to move to nose tackle after Pierce's opt-out; Wilson became a starter and three-down player only because of Anthony Barr's season-ending injury in Week 2; and Mata'afa is a guy who has bounced on and off the roster and was moved from tackle to end after the bye-week trade of Yannick Ngakoue, who was leading the team in sacks.

"I think [the defense] is coming into their own as young players," quarterback Kirk Cousins said. "I was a young player too, once and had my struggles in my first, second, third year, where you're figuring it out, even in my fourth year. Eventually, it starts to click and you can take your game to another level."

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