MEXICO CITY — If people needed more convincing about the New England Patriots defense, about whether this unit could be trusted down the road, there was plenty more evidence supplied Sunday.

Let’s just say it’s getting harder and harder to find reasons to doubt the defense.

The Patriots merely held Oakland’s offense to eight garbage time points.

Better still?

We saw the return of an opportunistic defense that made its biggest plays at the game’s most important times. Sure, the Raiders aided and abetted by dropping a ton of passes during the 33-8 drubbing in the thin air at Azteca Stadium.

But the bigger story was the turnovers the Patriots created and the momentum-changing plays that were reminiscent of championship defenses of old. Pick holes in the stats if you want, but the numbers keep adding up to a defense that’s getting the job done and setting the table for Tom Brady and the offense.

Six straight wins against a variety of quarterbacks and offenses shouldn’t be overlooked. On Sunday, it was Derek Carr’s turn to get swallowed up by a bend-but-don’t break defense that’s now forcing turnovers and making plays.

“We knew coming in, we were going to have to make a lot of plays,” said cornerback Stephon Gilmore. “Derek Carr’s a gunslinger and he has a lot of great receivers. We knew we (were up to) the challenge, so it feels good. Everyone’s getting better and better. We just gotta keep it going. We didn’t play perfect, but we made the plays we needed to win.”

The first four weeks of the season, all the big plays were going against them. Now, they’re the ones coming up with the game-changers.

The first such play Sunday came in the opening quarter. On third down with the Patriots up 7-0, safety Duron Harmon intercepted a pass that bounced off receiver Seth Roberts’ helmet. Cornerback Jonathan Jones was on the coverage.

Late in the second quarter, with the score 14-0, the defense came up big again after Carr completed a pass to Roberts at the 3. Jones was involved in this one as well, as he had his arms wrapped around the receiver. That allowed linebacker Marquis Flowers to alertly punch the ball away, and safety Patrick Chung recovered at the 7. The Patriots quickly moved into field-goal position and got three points when Stephen Gostkowski drilled a 62-yard field goal.

“Those plays were huge,” said Harmon. “Marquis’ play, in the red area, him not quitting on the play. We talk about it all the time, him running to the ball, he finished the play. Thirty seconds left, we still get three points … we talk all the time about turnovers being a big part of a team’s success.”

So are other key plays that stem the tide or change momentum. The defense made quite a few on third down, with the Raiders converting just 7 of 15 chances. Cornerback Malcolm Butler made a terrific open-field tackle on Amari Cooper in the second quarter to prevent a big gain and a first down.

Then in the third quarter, with the Patriots up 27-0, and the Raiders desperately looking for something, Coach Jack Del Rio went for it on fourth-and-1. Jamize Olawale was stuffed up the middle for no gain, with Chung making the stop.

Compared with where this defense was in September, it’s night and day. This marked the sixth straight game in which the defense has allowed 17 points or fewer.

“We did a good job of preparing,” said defensive captain Devin McCourty. “They made some plays, but we executed our game plan and did exactly what we wanted to do.”

Butler, Gilmore and Jones did a great job handling Michael Crabtree (six catches, 51 yards), Cooper (three catches, 28 yards, TD), and Roberts (five catches, 36 yards). Chung also was immense covering Carr’s favorite target, tight end Jared Cook, who was limited to two catches for 36 yards.

“At the beginning of the year, we were good, but we’d give up a touchdown and one chunk play,” said Harmon, “but now, we’re more consistent with the big plays. We’re more consistent with our run game, our pass game. Everything is more consistent.”

Butler said it’s just par for the course for the defense. They’re just now hitting their stride.

“We always start slow every year, and midway through the season, we just start bonding and making plays and getting better as a group,” said Butler. “It’s just happening now.”

They’re keeping the points down, they’re creating turnovers, they’re limiting big plays. Basically, they’re just rounding into form for the real games down the road.