The Post's Jason Reid reports an optimistic outlook for the Redskins after their first win and just before heading into their bye week. Photos by AP, Getty and the Washington Post. (The Washington Post)

Desperately needing a win to avoid falling to 0-4 as they entered the bye, the Washington Redskins gutted their way through an ugly game for a 24-14 comeback victory over the Oakland Raiders at Coliseum on Sunday.

The win came despite a disastrous start by the Redskins. Washington’s season-long third-down struggles persisted (they made only 5 of 16), the team surrendered a blocked punt for a touchdown and it fell into a 14-0 hole.

But sparked by an interception returned for a touchdown by rookie cornerback David Amerson, a seven-sack performance by the defense and an improved offensive showing in the second half, the Redskins overtook the Raiders and earned their first victory of the season.

Robert Griffin III orchestrated his first comeback of the season, completing 18 of 31 passes for 227 yards, a touchdown and no interceptions. Wide receiver Pierre Garcon led the team with six catches for 59 yards and a touchdown. Meanwhile, running back Alfred Morris had 71 rushing yards on 16 carries, and Roy Helu Jr. added 41 yards and a touchdown on 13 carries.

The Redskins now will report to team headquarters Monday and Tuesday and then depart for the bye. They’ll return to action Oct. 13 in Texas against NFC East rival Dallas, which lost, 30-21, in San Diego.

“It’s huge,” Griffin said. “We talked about it in the pregame. Our goal was to come out of here 1-3. There’s nothing else to say. We had to do whatever it takes to come out of this situation 1-3 going into the bye week, and I think that was big for us.”

Washington, trailing 14-3 early in the second quarter, received a much-needed boost from its defense when Amerson stepped in front of a Matt Flynn pass intended for Denarius Moore, picked it off and returned it 45 yards for a touchdown. It marked both the first interception and touchdown of Amerson’s career, and the play cut the Raiders’ lead to 14-10 with 11 minutes 9 seconds left in the second quarter.

After the half, the defense took the field first and forced a punt. Griffin & Co. took over, badly needing some kind of positive break — and they got it.

Facing third and nine from his own 12, Griffin avoided the rush and completed a pass to tight end Logan Paulsen, who made the catch roughly 23 yards upfield. Paulsen rumbled another 10 yards before a gang of Raiders defenders surrounded him and held him up long enough for linebacker Nick Roach to pull the ball free. Safety Charles Woodson recovered at the 43-yard line.

The Redskins avoided disaster, however, as the defense held the Raiders in check, and place kicker Sebastian Janikowski missed a 52-yard field goal wide left.

Washington capitalized by marching 58 yards in eight plays and scoring to take a 17-14 lead with 3:53 left in the third quarter.

Using runs of 12, seven and nine yards by Morris and a big 17-yard catch-and-run by Leonard Hankerson on third and three from the Oakland 29, the Redskins put themselves in scoring position. Then Griffin completed a five-yard pass to Garcon on a slant route into the end zone. Garcon dove across the goal line, jumped up and spiked the ball emphatically after giving his team its first second-half lead of the season.

Fueled by the offensive spark, the defense delivered again with a stand that featured sacks by Brian Orakpo and Barry Cofield on back-to-back plays. Oakland and Washington traded punts, but Cofield recorded another sack as the defense continued to put on its most impressive showing of the season.

“Give them credit,” said Flynn, who started in place of Terrelle Pryor (concussion) and completed 21 of 32 passes for 227 yards, a touchdown and interception. “They gave us some different looks than they’ve shown, and they did a nice job. We definitely feel like it’s a huge opportunity missed.”

On the next Raiders possession, Kerrigan recorded a sack-fumble, and Cofield recovered at the Oakland 49. Capitalizing on the short field, Washington needed only two plays to score. Griffin spun away from a would-be sacker, scrambled to his right and hit Helu in stride for a 28-yard catch-and-run that ended with the running back hurdling a defender and getting tackled two yards later. On the next play, Helu — who saw increased action with Morris nursing bruised ribs — scored on a 14-yard run up the middle.

The Redskins’ defense held again — denying the Raiders on fourth and one from the Washington 27-yard line. And Washington’s offense ran out the clock before punting to the Raiders with 21 seconds left and escaped Coliseum victorious.

“Feels great. We came out here and just wanted to get one,” cornerback DeAngelo Hall said. “We just wanted to get one, and that’s what we were able to come out and do. It’s a sigh of relief. We finally got that monkey off our back. Now we can go into the bye week and enjoy it a little bit, come back and get back to work.”

Initially, Washington appeared destined for its first 0-4 start since 2001.

The offense went 0 for 2 on its first two third-down attempts. (Santana Moss dropped the first, and Griffin overthrew Leonard Hankerson on the next). And then the Redskins had a punt at their own 9-yard line blocked and recovered for a touchdown.

On the block, Raiders defenders Rashad Jennings and Jeremy Stewart lined up over Washington’s Perry Riley Jr. on the left side of the line. Jennings, who had lined up outside, ran a stunt with Stewart, who crossed in front of Riley while Jennings cut to the inside before Riley could block him. Jennings blocked the punt, and Stewart recovered the loose ball in the end zone to put Oakland on the board.

The Redskins failed on their third straight third-down attempt and had to punt again.

The Raiders, meanwhile, showed the visitors how it’s done, stringing together a 10-play, 81-yard drive on which they converted three third-down attempts. Four plays defined the drive. On third and eight from the Oakland 33, Flynn completed a pass to Jennings, who broke three tackles and picked up 12 yards. On the next play, Flynn completed a 34-yard strike to Moore, whom Amerson lost up the right sideline.

Two plays later, the Redskins missed a golden opportunity as linebacker Brian Orakpo dropped a would-be interception. And on the next play, Flynn fired an 18-yard touchdown pass to tight end Mychal Rivera, who was flanked by Hall and safety Jordan Pugh.