It all came down to a final goal-line stand, and Minnesota's defense turned up the heat in Houston.

After allowing three consecutive pass plays of 23, 15 and 16 yards, the Vikings tightened up and stopped the Texans four times from inside the 5 to wrap up Minnesota’s first win of the season.

The Vikings secondary came up big in crunch time for a 31-23 victory.

On first-and-goal from the 4, safeties Anthony Harris and George Iloka – who had stepped in following a second-quarter ejection of Harrison Smith – joined forces to stop Texans running back David Johnson at the 1. Harris stopped Johnson for no gain on the following snap.

"Once you get down there in the red zone, [teams] are going to try to do what they do best. So it's all about just knowing what they want to do, knowing our coverage, how we need to be, how we need to fit, and then just playing everything honest," Harris said. "Reading your keys and just attacking. On those two plays down at the goal line, me and George just tried to do our job, and then once we went through our execution as far as technique and assignments, just go and attacking downhill."

When a third-down speed-option miscue resulted in Johnson recovering a fumble credited to QB Deshaun Watson, Iloka was immediately there to tackle Johnson for a loss of 4.

Harris was asked about the play during his postgame media availability.

"We've seen some plays where they do read-option with [Johnson] on the inside and he's exploded a couple times, but also they've had on film where they're running that speed option," Harris explained. "So it's just all about knowing the options that they have and just playing honest – not really guessing but just reacting to the technique and the things you go through all week, and hopefully that leads you to success."

After the stop by Iloka, the Texans were forced to go on fourth down.

Watson threw to wide receiver Will Fuller V, who was covered by Vikings cornerback Holton Hill. Fuller managed to make a one-handed grab, but the initial ruling of a touchdown was overturned after review of the play showed Fuller did not have control of the ball as he hit the ground.

Harris said the team emphasized "staying settled, staying poised," when Houston started to come from behind.

"[We were] continuing to believe in our abilities, believe in what the coaches want us to do and then just going out there and executing – everybody just doing their job and attacking, playing aggressive," Harris said. "Guys did that when we got down in the red zone, trying to hold them out there in the last drive.

"I believe everybody did a good job of knowing their assignments, executing and then just continuing to attack the ball whether it's in the air or on the ground," he added.

The Texans were not allowed a touchdown on any of their three trips inside the Vikings 20-yard line. In fact, Houston had 10 plays from at or inside the Minnesota 10 and totaled just six points.

Entering Sunday's game, the Vikings defense tied for seventh in the NFL in red-zone percentage, limiting opponents to a 50-percent success rate. Factoring in their Week 4 performance, the Vikings have only allowed opponents to score a red-zone touchdown on 41.2 percent of attempts.

"We spend a lot of time inside the 12-yard line, and we've been decent at it for the most part. I think our guys understand how to play in that area," Zimmer said. "There's two areas there – you have to defend the down-and-distance, plus you have to defend the goal line. So we try to teach our guys like that all the time."

Minnesota also played well on third downs, allowing Houston to convert on three of 12 attempts (25 percent).

The Vikings forced the Texans to go three-and-punt on their first two drives, and again late in the third quarter. Midway through the second quarter, Eric Kendricks went airborne to break up a pass to Brandin Cooks on third-and-9.

Watson was sacked three times, including by Vikings rookie D.J. Wonnum, whose first-quarter takedown was the first of his NFL career. Watson finished the day 20-of-33 passing for 300 yards and two touchdowns with a passer rating of 110.7.

Minnesota tried to capitalize on Houston's shaky run game, limiting Johnson to just 3.9 yards per carry and 63 total yards. Duke Johnson added another 24 yards on the ground on five attempts, and Watson netted nine rushing yards. Fuller led the Texans in receiving with 108 yards through the air.

There were ups and downs for the Vikings defense, which allowed five plays of 20-plus yards, including a 43-yard bomb to Fuller and a pair of 24-yard touchdowns by Fuller and Minnesota native Kenny Stills.

Zimmer was pleased overall with the unit's production, though, especially considering how shorthanded Minnesota is on that side of the ball. In addition to Danielle Hunter and Anthony Barr being on IR, the Vikings were without cornerbacks Mike Hughes and Kris Boyd.

"I thought we played really, really well early in the ball game. We got a bunch of three-and-outs, and the time of possession was really good in our favor. I thought we were good on third downs today. We were good in the red zone," Zimmer said. "We didn't give up as many big plays as we had in the past. [Jeff] Gladney got beat on the one long one. Then we got misaligned on the other one late in the ball game. But they battled.

"There were a couple fourth downs that we had to compete, and it was nice to see them compete and fight, a bunch of young guys," Zimmer added. "We had linebackers in there (Todd Davis and Ryan Connelly) that had been here less than [a month]. Three of our five linebackers didn't start training camp with us, I think is what I was told. Playing with a lot of young guys. So that's just the way it is."

And considering Smith's ejection on top of everything else, the Vikings could have been in quite a predicament.

Zimmer said he "saw mistakes" in Iloka's outing but wasn't too critical of the safety who signed with the Vikings on Sept. 17 and was activated from the practice squad to active roster on Saturday.

"You know, he was actually our backup nickel today in case something happened to Gladney, so he was preparing most of the week at nickel," Zimmer said. "I had to actually ask him on the sideline if he knows what he's doing at safety."

Harris also gave props to Iloka and others who adjusted on the fly when Smith was disqualified.

"I think for him to leave the game, it asked for guys to step up," Harris said. "Our young guys did a good job of staying together, continuing to play through adversity and finding a way to make plays when we need them."

It may not have been perfect, but a win is a win – and the Vikings are happy to have one in the bag.

"It's a tough league to win in, no matter who you are or wherever you play. Coming in here, it wasn't any big pressure; it was just, 'Let's go out and do what we do,' " Harris said. "That's just playing football. Go out, execute your job, have fun with it, and then don't worry about the end result. If we take care of what we need to, each drive at a time, one play at a time, we'll get the results we want at the end of the game."