PITTSBURGH — Week 15’s game of the week was more of a must-win for the Pittsburgh Steelers than it was for the New England Patriots. And that’s just what the Steelers did.

The Steelers put their nose to the grindstone and efforted it out in a 17-10 win over the Patriots at Heinz Field on Sunday to avoid losing four straight games. While it first looked like it would be a shootout in the making, the game came down to which defense would hold up the longest. The answer was the Steelers’, which halted the Patriots on a late fourth-quarter drive to seal the win.

The 9-5 Patriots now hold the No. 3 seed in the AFC playoffs behind the Kansas City Chiefs and Houston Texans. They would have to play on Wild Card Weekend as the playoffs are currently constructed.

Here’s why the Patriots lost:

RUN DEFENSE IS A SIEVE
The Patriots’ run defense continues to be porous. With Le’Veon Bell probably on a beach somewhere and James Conner out with an injury, the Steelers had no business picking up 6.3 yards per carry.

Yet that’s exactly what happened. If the Patriots’ don’t trust Danny Shelton, who was a healthy scratch for the third straight week, then they need to cut bait and bring in a defensive tackle who can contribute in the middle of the field. This current unit isn’t getting the job done.

Steelers rookie running back Jaylen Samuels had 19 carries for 142 yards.

PENALTIES
The Patriots were flagged 14 times for 106 yards. The penalties included five false starts, three offensive holding penalties, two defensive holding penalties, one offside, a delay of game, a defensive pass interference, an ineligible man downfield on a punt and an illegal formation.

A holding penalty by left guard Joe Thuney late in the fourth quarter led to three low-percentage throws by Patriots quarterback Tom Brady to end the game.

DROPS
The Patriots had three key drops — two from Julian Edelman and one from Josh Gordon — which helped stall the offense. Brady was 25-of-36 for 279 yards with a touchdown and interception. He could have used some help from his receivers. He also threw a costly interception when the Patriots were in Steelers territory midway through the fourth quarter.

CONSERVATIVE PLAY
The Patriots played it safe on multiple occasions in Sunday’s loss. They punted on fourth-and-4 from their own 47-yard line, again on fourth-and-1 from their own 40 and chose to kick a field goal facing fourth-and-1 from Pittsburgh’s 10-yard line.

Thumbnail photo via Dec 16, 2018; Pittsburgh, PA, USA; Pittsburgh Steelers wide receiver James Washington (13) runs after a catch against the New England Patriots during the second quarter at Heinz Field. Mandatory Credit: Charles LeClaire-USA TODAY Sports