The Patriots’ defense had a confident start, unlike last year’s season opener

Opening night 2017, the Patriots started their NFL season amid heady joy and high expectations, hanging their fifth Super Bowl banner before hosting the Kansas City Chiefs.

Opening day 2018, the Patriots started their NFL season amid the sting of regret and lost opportunity, determined to forget their fifth Super Bowl loss before hosting the Houston Texans.

Opening night 2017, the Patriots’ defense took the field and was summarily torched by those Chiefs, a mess of miscommunication and missed assignments combining to surrender 42 points and 537 yards (the most in a game of Bill Belichick’s coaching tenure), allowing touchdown drives of 90, 92, 75, 90, 60, and 79 yards. The sense of panic was palpable, with roster changes and coaching moves invited to a full-on second guess party.

Opening day 2018, the Patriots’ defense was crucial to a 27-20 victory over the Texans, a study in symmetry and balance combining to hold dangerous quarterback Deshaun Watson in check and keep superior wide receiver DeAndre Hopkins from lighting it up, three sacks, one interception, and a fumble recovery combining to hold Houston to 325 yards. With an aggressive defensive line (according to Next Gen Stats, Watson was under pressure on 7 of his 13 first-half pass attempts) and a patient secondary (cornerback Stephon Gilmore, last year’s new guy, didn’t allow Hopkins a catch until the second quarter), the defense took a far more confident, calm step into the season.

“To get the first one is big,” cornerback Eric Rowe said. “You can climb up from there. Last year the loss to the Chiefs, we were kind of in a hole. You don’t want to start in a hole. You want to start on top and go from there. We’ve preached that all of training camp, that we needed to be a good communication team. We knew we could show it on the field.”

The difference in tone was set early. Watson, who’d run all over the Patriots while throwing for 301 yards in an early-season, pre-ACL injury game against New England last year, fumbled his first touch of the ball, a botched handoff at his 20-yard line that was recovered by Dont’a Hightower at the Houston 19. Three plays (and a penalty) later, Tom Brady connected on a 21-yard touchdown pass to Rob Gronkowski, their 76th career touchdown connection, giving the Patriots a 7-0 lead. But the defense wasn’t done announcing its presence, with the next exclamation point served following a Brady mistake. Intercepted when Tyrann Mathieu snared a tipped ball with 4:12 to go in the first quarter and still holding onto that one-score lead, Brady set Houston up at the 17-yard line. But one incomplete pass, one rush for no gain, and one combination sack by Trey Flowers and Deatrich Wise and the Texans settled for a field goal.

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“Whatever the offense gives us, as far as if it was coming out of their end zone or going into their end zone, however they got down there, we didn’t worry about it,” Flowers said. “It was just a next-play mentality and we just banded together. I think we responded well to the sudden changes.”

This time last year? Not so much. Some of those growing pains were to be expected. Back then, Wise and fellow defensive lineman Adam Butler were fresh-faced rookies, not yet ready or able to contribute. Gilmore had arrived from Buffalo with a big free agent contract and plenty of expectation but needed time to adjust to new schemes, new terminology, and even new tackling and coverage techniques. But no one expected it to be quite as tough as it turned out. Four games into the season, at 2-2, the Patriots’ defense had given up a league-worst 1,827 yards and a second-worst 32 points per game. In fact, in their Week 4 game against Carolina, the 444 yards of offense they gave up actually improved their per-game average.

They would eventually figure things out, not before losing the likes of Hightower to a season-ending injury, but still improving nearly every week until reaching the Super Bowl. What happened in Minnesota has been well-documented, from the mysterious benching of Malcolm Butler to the maddening inability to stop Philadelphia’s winning comeback, enough to fuel yet another renaissance for a unit intent on doing its part.

“It definitely feels better,” Gilmore said. “Sometimes it’s a little different the way they coach, techniques are different here than where I was at. I have to get used to those. I take all coaching and try to do the best I can. We’ve got great coaches around here. The stuff that they teach, it works. Some stuff I didn’t even know before I got here, I know now. The communication was good. That was one thing we came into the game and said we had to have great communication, everybody had to be on the same page, and if we do that they can make a great catch and we can live with that. We just can’t let up big plays and make it easy for them.

“It was a win, so I’m happy about that. I feel better obviously on the field. I’ve got a lot of great players around me, they make me better.”

The whole unit was better, flourishing under de facto defensive coordinator Brian Flores, who seems willing to be slightly more aggressive than Matt Patricia, now the head coach in Detroit. All of this is new to cornerback Jason McCourty, who didn’t get a lot of snaps in his first pro game alongside twin brother Devin, but who saw a group of defenders all on the same wavelength.

“It was awesome,” Jason said. “I wasn’t out there for the most part, but seeing the continuity, the chemistry, guys coming to the sideline talking about everything, seeing that was great. I think you look at our secondary right now, these are all guys that now have been playing with each other for a while, and that type of communication and continuity, all throughout last season and going through adversity, building to get to the big game, coming up a bit short, and now all spring, all summer, you can see that there’s more of a brotherhood, more of an understanding where each guy is going to be.”

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Tara Sullivan is a Globe columnist. She can be reached at tara.sullivan@globe.com. Follow her on Twitter @Globe_Tara.