Things looked easily in hand for the Browns with a 26-14 lead and just 2:39 remaining.
But then the Patriots had an 11-play, 82-yard touchdown drive, a recovered onside kick and a 29-yard pass interference penalty that set up the game-winning touchdown throw to Danny Amendola.
Yes, the 2013 Patriots stole yet another victory in thrilling fashion. This squad might be too banged up to win a Super Bowl, but it's certainly been a fun ride.
Perhaps even bigger news than the miracle victory is that Rob Gronkowski's injury did not look good.
Here are the takeaways for Sunday's game, including the latest on Gronk's knee and the Pats' prospects going forward without their big tight end.
The Browns' pass rush got to Tom Brady and sacked him four times, many in key moments with the Pats' protection breaking down quickly.
The Patriots are on their third right tackle, Will Svitek, who was beat for one of the sacks.
The protection had one of its most inconsistent nights. Usually when it has a bad start, it corrects and plays well for the remainder of the game.
But against the Browns, it was up and down, until late in the third quarter when the offense started moving the ball and putting together double-digit play scoring drives.
The offensive line has been somewhat uneven most of the season, perhaps one of the biggest reasons for its constant slow starts.
With Aaron Dobson and Kenbrell Thompkins inactive, rookie Josh Boyce stepped up, playing his most significant snaps of the season.
He finished with three catches on five targets for 49 yards, including a long of 22 yards.
Of course, there was also the drawn pass interference call that set up the game-winning touchdown. It was Boyce's speed that set up that call, whether it was a good call or not.
With Rob Gronkowski's injury, the Pats will need a playmaker like Boyce to step up. He could have a big role down the stretch if Dobson and Thompkins can't get healthy.
Boyce has always had exceptional speed but now looks like he's finding the confidence to use it.
Shane Vereen led the Patriots with 12 catches for 153 yards with a rushing touchdown. When the Pats needed a weapon to replace Gronkowski, it was Vereen who stepped to the forefront.
Vereen's speed in space and downfield catching ability were on display once again. With Julian Edelman, Danny Amendola and Josh Boyce largely held in check, Vereen carried the Pats offense for large chunks of the game.
The Pats will continue to need great things out of the third-year running back, who is quickly becoming an offensive star.
The Pats inserted Sealver Siliga as their starting defensive tackle over Joe Vellano, and the move sparked a revival of run defense, at least early in the game.
Dane Fletcher was worked in a bit more, as was rookie Jamie Collins. It will be interesting to break down their snap totals. Both seemed to get extensive work.
The Pats went back to some more 4-3 fronts and did a good job forcing the Browns to throw the ball more.
That's where the problems started.
The Pats did a good job stopping the run early in the game, but when the Browns then focused on their passing game, they found success.
Jason Campbell finished 29-of-44 for 391 yards and three touchdowns, and essentially picked the Pats defense apart through the air for most of the game.
For the second time this season, the Patriots defense failed to force a turnover. Those are drying up at the wrong time of year.
The pass rush was sporadically effective, registering just one sack and five QB hurries. But the coverage and tackling weren't much better.
For all the talk of Aqib Talib being a shutdown corner, he certainly gave up some plays to Josh Gordon.
The Pats' pass defense looked far from elite against the Browns, and it needs to tighten it up on all levels.
Tom Brady knows it. Bill Belichick knows it. You and I know it.
The Patriots offense has been ice-cold in the first half since the bye week, and it can't seem to get out of the funk.
The Patriots have relied on furious comebacks in the second half and almost always seem to pull them out.
Against a team like the Browns, the hole was only 6-0 at the half. Against playoff teams, that hole will be double digits.
The Patriots have to figure out a way to start fast and finish strong, and they have two tough tests coming back-to-back on the road. The Patriots are still very much in the driver's seat for a division title and a bye, but they'll need to put together a full game at some point.
Still, you have to love the heart. There's no quit in them.
Early reports on Rob Gronkowski are that he tore his ACL, per Mike Garafolo of Fox Sports.
If true, this is a critical blow to an offense that was just finding its stride. Gronkowski has had five surgeries in the last 13 months, and an ACL reconstruction would make his sixth surgery another significant one.
It's truly disappointing because Gronkowski is a rare talent, and these mounting injuries seem to keep getting more severe. How long can the Gronk handle this kind of punishment?
As for the Patriots, they'll have to lean more heavily on fullback James Develin and hope that Michael Hoomanawanui can return from injury and build on what was starting out to be a solid season before the return of Gronkowski.
The Pats struggled in the red zone and on third down without Gronkowski, and his return immediately fixed those problems. Now, the Pats will have to rely on Julian Edelman and Danny Amendola to win inside with quickness.
Gronkowski will no longer be around to pull coverage. Things will get a little harder on all of the receivers.
The loss of Rob Gronkowski is possibly a devastating one; the Patriots must learn to live without him on the road in Miami and Baltimore, two games that will tell us if the Pats offense can be elite without its big tight end.
The Patriots have won double-digit games in a season plenty of times before, but this one feels different than any time recently.
The Pats have been devastated with injuries to every major organ of the team outside of Tom Brady and Devin McCourty. Somehow they've come out of it all and are 10-3 and sitting with the No. 2 overall seed in the AFC.
It's pretty remarkable.
Can this team win a Super Bowl? It will certainly be a lot tougher without Rob Gronkowski, but there's still some time to figure out what works best.
It's not like 2009 when Wes Welker was lost in Week 17 and the Ravens were coming to town the next weekend.
The Patriots have been a fun team, and they'll likely earn a home playoff game and be a tough out for whoever has to play them.
But they are not unbeatable, and if they keep digging themselves into holes, they won't keep crawling out of them.