The Patriots weren't forcing turnovers, with just six forced in their last five games, and couldn't seem to make any big, game-changing plays. This was a departure from earlier in the season and the last two seasons, when the Patriots have pretty much won or lost based on turnovers.
But against the Ravens, the Patriots defense finally returned to its big-play ways, coming up with four turnovers.
Stops on fourth downs are essentially turnovers as well, and the Patriots tacked on three of those. They were all game-changing plays in the second half that prevented any Ravens comeback.
Let's take a closer look at the three fourth-down stops, and the schemes and players that put the Patriots in position to be successful.
Fourth Down No. 1
Situation: Third quarter, 12:23 remaining, 4th-and-3.
Patriots 17, Ravens 0
The Ravens needed a score on their first possession of the second half to set the tone for a comeback, and they got all the way to the Patriots' 39-yard line with an impressive drive.
Good coverage and a Chandler Jones pressure forced an incompletion on 3rd-and-3.
The Ravens, just outside of field-goal range, decided to go for it on fourth down.
The Patriots disguise their coverage and are in zone. Logan Ryan correctly played the deeper corner route. Flacco could've had the easy first down with the underneath throw, but he likely assumed Ryan would be either in man or dropping only to the sticks.
Ryan showed good range and was able to get a hand on the ball. It's no surprise he picked off two passes in this game. His progression has been impressive.
The Patriots' defense had struggled after moving to more zone coverage in the second half of the season, but this play by Ryan signals improvement not only for him, but for the rest of the secondary.
Being able to play tough man-to-man is necessary for any defense to be good, but also being smart in zone coverage and reading patterns will make a defense great.
This solid coverage gave the Patriots a boost to start the second half.
Fourth Down No. 2
Situation: Third quarter, 3:03 remaining, 4th-and-1
Patriots 20, Ravens 0
With their backs against the wall, the Ravens put together their best drive of the day, getting all the way down to the Patriots' 4-yard line.
This drive included a 42-yard completion to Torrey Smith, and it looked like the Ravens had found a rhythm on offense.
The Ravens needed just one yard and likely would've also gotten the touchdown if they executed the right play. That would've put them two touchdowns from the lead, not an impossible proposition given how hot and cold the Patriots have been this season.
Flacco saw the space inside and decided to call a quick snap dive, after a pass play was likely called in the huddle.
The key to the stop was Sealver Siliga, who crashes down the line and disrupts everything. He gets all the way into the backfield, creating a complete logjam in the A gap and forcing Ray Rice to cut outside.
Rob Ninkovich is quick enough to swim past Michael Oher, then strong enough to finish Rice off after Siliga had tripped him up.
This is great all-around defense but also just an outstanding play by former practice squad player Siliga. Siliga has overtaken Joe Vellano as a starter and continues to impress.
This fourth-down stop might be his best yet. He'll need to keep it up in the playoffs.
Fourth Down No. 3
Situation: Fourth quarter, 6:46 remaining, 4th-and-10
Patriots 20, Ravens 7
With time running out, the Ravens were still within striking distance. But they got stuck at midfield with three straight incompletions to set up a 4th-and-10. With a stop, the game would be essentially over. New England would be set up with great field position and the chance to go up by more than two touchdowns.
This final play is a great example of all-around team defense.
First, the coverage is tight, leaving Flacco with no clear option on his first two reads. The secondary did its part. It was up to the pressure to finish the play off, and that's what it did.
Dont'a Hightower, who has also really come on in the last few games, comes on a Green Dog blitz. Though he gets knocked down, he's athletic enough to pop right up and bring pressure on Flacco. He's also quick enough to force a bad throw.
The coverage held up throughout the play as well, something that has haunted the Pats in recent weeks as well.
When the coverage and pressure work in conjunction, it makes for great defense. The Patriots had some of their best balance of the season against the Ravens.
Pats' Defense Has the Potential
There was cause for concern in recent weeks when the Patriots defense was failing to come up with any big plays. Though they were often showing flashes, it was never consistent, and they weren't getting their hands on any passes.
Against the Ravens, it all just seemed to click.
There's no assurance that the Patriots defense can put together another performance like that one, but it proves that they are actually capable of being pretty good.
That confidence boost could pay the biggest dividends.
But can they put three (or even four) straight games of that play together in the next five weeks?
It's the Patriots, so it's sure to be interesting.