Dolphins' incredible final play caps off big step back for Patriots' D

Dolphins stun Pats with miracle walk-off TD (0:59)

Kenny Stills' catch triggers a series of laterals that ends up with Kenyan Drake, who throttles to the house on an improbable walk-off touchdown. (0:59)

MIAMI GARDENS, Fla. – Coming off their most impressive performance of the season, the New England Patriots’ defense took a major step back in Sunday’s 34-33 loss to the Miami Dolphins at Hard Rock Stadium.

It doesn’t get much worse than giving up a desperation 69-yard touchdown on the last play of the game. The performance sparks some old questions about the unit, and how much the Patriots can rely on it as they hope to make another postseason run.

Once again, South Florida was anything but a day at the beach for the Patriots, who are 1-5 on the road against the Dolphins since 2013. Tom Brady is 7-10 on the road against the Dolphins, who are one of just three teams who have faced Brady multiple times and have winning home records, according to ESPN Stats & Info.

The final play – with tight end Rob Gronkowski lunging helplessly near the goal-line as Kenyan Drake took a lateral 52 yards to the end zone -- was a breakdown of epic proportions. How does that happen?

It was the dagger for a defense that couldn’t slow down the Dolphins’ running game for most of the day.

The Patriots had opened the game in a three-safety nickel defense, meaning they were essentially playing a six-man box. That invited the Dolphins to run the ball, which is a matchup the Patriots have had success with in the past.

But in the 80-degree heat and humidity, the Patriots struggled to control blockers at the line of scrimmage, and shedding blocks and tackling from linebackers and defensive backs was a similar struggle.

It was easily the most rushing yardage (189) the Patriots had allowed all season.

Meanwhile, the Dolphins hadn’t had such success on the ground since Week 16 of the 2016 season.

The Patriots made a second-half adjustment to play more base defense, giving them a seven-man box that was more stout. The results improved slightly, but by that point, there was little margin for error, in part because of missed opportunities from the offense and special teams earlier in the game.

Quarterback Tom Brady made an uncharacteristic mental mistake at the end of the second quarter by taking a sack when the team didn’t have any timeouts, which cost the team at least a field goal. And kicker Stephen Gostkowski missed an extra point and a 42-yard field goal. It was his shortest missed field of the season, and he was 37-of-37 on extra points before Sunday, according to ESPN Stats & Info.

The Patriots, who drop to 9-4 and could have clinched their 10th straight AFC East title, will now look to do so with a win next Sunday in Pittsburgh.

While it doesn’t all fall on the defense, the Patriots will need a much better performance in Pittsburgh to have a chance.