By Morris Phillips

Facing a potential game-winning drive by the Eagles, and desperately needing to avoid the dreaded 1-3 start to their season, the 49ers’ defense went back to basics on Sunday.

Trust your coaches.  Believe in your teammates.

And in the craziest game of the season to date with Philly’s hyperactive offense blacked out, the 49ers’ twists, turns and unfortunate touchdown returns, going back to the basics actually worked and the 49ers pulled out a heart-stopper in a 26-21 win.

“We were desperate to get this win,” Ahmad Brooks said.  “Losing two straight games to conference teams, we needed to get back on track.  We just needed to get back to the basics.”

After the game, multiple players recounted how the team practiced this week, certain in its schemes and methods, while focused on refining things in response to the penalties and breakdowns that marred the previous two losses.  Against the Eagles and Coach Chip Kelly’s spread attack, the 49ers stayed in their base defenses, made tackles and relied heavily on defensive coordinator Vic Fangio’s ability to recognize play tendencies based on how the Eagles lined up, which really aided the team’s final stand with Philadelphia poised to score and take the lead.

From Kelly’s perspective, three missing starters in the Eagles’ offensive line may have been as big a factor as any vanilla 49ers’ defense.  Afterwards, he admitted the injuries caused him to limit the options in the team’s offensive playbook which may have then aided the 49ers’ ability to anticipate certain plays.

“We’re not very good up front right now,” Kelly admitted.  “We’ve got a lot of guys banged up.  That’s not an excuse.  That’s just the reality of it.  Jason Peters is the only guy who’s playing the position he started the season at.”

But whatever the combination of factors, they all conspired in the 49ers’ favor:  the Eagles gained just 213 total yards, only 22 via the rush, and held the ball for fewer than 18 of the game’s 60 minutes.  And one of the NFL’s very best runners, LeSean McCoy was rendered a non-factor with 17 yards on 10 rush attempts.

It marked just the second time since Kelly came to Philadelphia that his offense failed to score a point.  But the 49ers couldn’t achieve any relief from adversity late in the contest, due to three early miscues that all resulted in Eagles’ touchdowns—get this—without Philly’s offense having anything to do with it.

When the 49ers’ initial possession of the day went backwards, the Eagles caught them in a punting situation at their own 2-yard line allowing Trey Burton to bust in from an overloaded side of the formation and block Andy Lee’s punt.  Brad Smith recovered the ball in the end zone for the Eagles and they led, 7-0 less than three minutes into the game.

Then after the 49ers pulled to within three, 10-7, in the second quarter, and after Colin Kaepernick and Frank Gore hooked up on a nifty 55-yard catch and run play, the Eagles’ defense struck courtesy of Malcom Jenkins’ interception and return that covered 53 yards.

Minutes later, Darren Sproles was at it on an 82-yard punt return that gave Philadelphia an 11-point lead with all points coming while the Eagles’ offense rested.

“Most of the time, you’re not supposed to win games like that if you give up a blocked punt for a touchdown and give up a punt return for a touchdown,” fullback Bruce Miller said.  “It doesn’t usually go in your favor.”

But the 49ers did win, weathering the early squandered points and by turning back the Eagles on four straight plays inside the 10-yard line in the final minutes.  The Eagles got to the two-yard line for the last two plays but Nick Foles predictably threw on both downs.

The first of those plays ended when Foles’ throw landed out of reach of tight end Brent Celek.  Then on fourth down, Foles rolled right a la Joe Montana on the Catch, but Jeremy Maclin couldn’t corral the ball along the end-line at the back of the end zone.

With the win, the 49ers improve to 2-2 with a visit from former teammate Alex Smith and the Chiefs up next on Sunday.

Gore topped 100-yards rushing against the Eagles for the fourth time since 2008.  Vernon Davis and offensive tackle Anthony Davis both left the game early with injuries, but according to Davis himself, his back contusion isn’t serious.

Bethea was the unquestioned star of the defense by forcing Zach Ertz to fumble which was then scooped up by teammate Perrish Cox.  Bethea also recorded his first interception as a 49er in the second half.  In, all the Eagles coughed up the ball four times, two fumbles and two picks.

And the 49ers limited the penalties, committing 10, but none of those by the defense.