This time, the Eagles’ pass rush on Brock Purdy was neutralized by 49ers coach Kyle Shanahan’s adjustments

Defensive tackle Fletcher Cox doesn’t like this unfamiliar feeling in his stomach.

After five straight wins, the Eagles floating on cloud nine with the NFL’s best record at 10-1 going into Sunday night, they suffered a gut-punch of a 42-19 loss to the San Francisco 49ers. Despite limiting the 49ers to minus-6 net yards of offense on six plays in their first two drives — both three-and-outs — the Eagles failed to replicate that same defensive success, especially up front, and allowed six touchdowns on six consecutive drives.

“We knew we had to get them out of rhythm,” Cox said. “But we did. Early in the game, we did. But kind of later, we had some leakage in the run game. And again, I think we all feel it. We all got that feeling in our stomach. The feeling that we never want to feel. We didn’t feel this for a long time.”

Edge rusher Haason Reddick started the night off strong by reacquainting himself with 49ers quarterback Brock Purdy. On the 49ers’ second play of the game as Purdy attempted to escape the pocket, Reddick disengaged from right tackle Colton McKivitz and brought Purdy down from behind for the sack.

On the following series, Reddick broke into the backfield again on second-and-14 and Purdy threw the ball incomplete. However, even though the defense was forcing the 49ers off the field quickly thanks to their ability to get Purdy under duress, the Eagles offense only had a pair of field goals to show for it by the beginning of the second quarter.

“We got to capture those moments,” defensive end Brandon Graham said. “We’ve got to score points. Field goals is cool. But we’re really trying go up fast, capture that momentum. But we didn’t do that today as a collective. We’re gonna own that together.”

» READ MORE: The 49ers shredded the Eagles defense. Here are our grades.

That momentum shifted when the 49ers took the field for their third series of the game. They posted their first positive-yard play of the night two minutes into the second quarter when Purdy connected with receiver Brandon Aiyuk for a 12-yard gain on an out route.

After the game, Purdy stressed the importance of getting the ball rolling and creating a positive play in the wake of their first-quarter offensive woes.

“Especially for myself as a quarterback, I just needed to see myself completing a ball, get a completion, get things rolling, and we did that,” Purdy said. “Kyle [Shanahan] called some plays to allow us to get the ball out of my hands pretty quick to get into a rhythm. Once we did that, we rolled from there, and we didn’t look back.”

Purdy led the offense down the field as the drive continued by finding tight end George Kittle for a 32-yard gain on blown coverage from the Eagles. Eventually the 49ers reached the red zone and the Eagles had a chance to hold them to a field goal when they forced Purdy to run out of bounds on first down and to throw an incompletion on second down.

But on third-and-goal from the 4-yard line, defensive end Josh Sweat incurred a neutral-zone infraction penalty, bringing the 49ers half the distance to the goal line. On the subsequent play, Aiyuk hauled in the 49ers’ first touchdown of the night to put them up, 7-6.

Later on, with less than two minutes remaining in the first half, the 49ers were driving just outside the red zone. On second-and-10 from the Eagles’ 24-yard line, the officials deemed Sweat offside, a 5-yard penalty. Receiver Deebo Samuel ripped off a 14-yard run on the ensuing play, ultimately leading to a running back Christian McCaffrey 3-yard rushing touchdown to give the 49ers a 14-6 lead at halftime.

“I know Sweaty’s feeling bad on the offsides, because lining up in neutral zone, we always talk about just little stuff that could hurt us,” Graham said. “I know that I got his back. I know that he’s gonna make it right and we’re gonna be good.”

As the night went on, Shanahan continued to adjust his game plan to help keep the Eagles’ pass rush from being disruptive. Instead of hanging back in the pocket, Purdy made a point to get the ball out quickly to compensate for his offensive line’s struggles to contain the Eagles’ pass rush.

According to NFL Next Gen Stats, Purdy had 2.85 seconds to throw, tied for seventh fastest in the league in Week 13. He finished the night with 19 completions on 27 attempts (70.4% completion) for 314 yards, four passing touchdowns, and a 148.8 rating.

“A lot of quick passes, underneath passes, try to eliminate the rush that way,” defensive tackle Milton Williams said. “Screens, and they’re blocking them up pretty good and they’re taking it. So we just got to be better getting out of the stack and running. And try to get them on the ground and live another play.”

When Purdy wasn’t leaning on the quick passing game, Shanahan was scheming up ways to get the ball in the hands of McCaffrey, the league’s leader with 1,032 rushing yards. McCaffrey didn’t have a carry until the second quarter, but he ultimately collected 93 yards and a touchdown on 17 carries. Samuel made the most of his touches, too, posting a game-high 7.3 yards per carry for a total of 22 rushing yards.

Getting behind the sticks early prevented the 49ers’ run game from getting in an early rhythm, but they started to click in the second quarter and never let up.

“There wasn’t any big difference, it was just our defense keeping us in the game and allowing us to just be patient and continue to do what we planned and play good football,” Shanahan said. “We didn’t do that for two drives, but we like to say if we’re in the game it’s a matter of time and we got it going there on the third drive.”

In the third quarter, Cox got the best of McKivitz and sacked Purdy on the first play of their second possession of the half. But otherwise, the 49ers found a way to keep the Eagles from wreaking havoc up front in the second half, both in the pass rush and in run defense.

Now, Cox and the Eagles will have to find a way to rid themselves of that foreign feeling in their stomachs.

“The thing I do know about this team, is what makes it so special, is the way that we respond,” Cox said. “Everybody to kind of go back, and not that everybody’s not been going back, but we’ll take a break and come in and fix things tomorrow and get ready for the next game.”