A potentially season-ending injury for quarterback Robert Griffin III overshadowed the first victory of the year for the Washington Redskins on Sunday.

Just about everything, outside of Griffin’s health, went right for the Redskins as they thumped the Jacksonville Jaguars, 41-10, in front of a FedEx Field crowd announced at 80,037. The win snapped a nine-game losing streak dating from last season.

It was the team’s first win since a 30-24 overtime victory against the San Diego Chargers in Week 9 of 2013. The defense racked up 10 sacks, and the special teams units generated some spectacular returns.

Alfred Morris rushed for two touchdowns, tight end Niles Paul had a career day with 99 receiving yards and a touchdown, Kirk Cousins had two touchdown passes and linebacker Ryan Kerrigan led the defense with four sacks. That all added up to get Jay Gruden his first victory as an NFL head coach.

But shortly after the game clock hit triple zeroes, all thoughts shifted back to the fallen quarterback, who in the first quarter suffered a dislocated ankle and seems likely to miss significant time, if not the remainder of the season.

Because a dislocated ankle can come as a result of either a break or ligament tear, an MRI exam is needed for doctors to know the extent of the injury, the next course of action and Griffin’s recovery time. At the minimum, however, he is believed to be facing a six- to eight-week recovery.

Griffin said he has a 10 a.m. appointment Monday for the MRI exam.

Griffin wasn’t the only offensive starter injured Sunday. Wide receiver DeSean Jackson left the game late in the first quarter with a sprained left shoulder, and left guard Shawn Lauvao left in the fourth quarter with a sprained right knee.

After a promising start — Griffin completed two of his first three passes and rushed for 22 yards on two carries — he made a play that looked impressive but ended in disaster.

With Washington on its second offensive possession and facing second and four from the Jacksonville 39-yard line, Griffin rolled to his right and slipped a diving tackle attempt from Jaguars linebacker Paul Posluszny. But the quarterback’s left foot came down awkwardly after stepping free of Posluszny’s grasp. Griffin threw off of his right foot, back across his body and falling out of bounds, and completed a 19-yard pass to Jackson.

Griffin made a concerted effort not to land on his left foot as he came down following the jump pass. The quarterback rolled over and lay face down on the sideline, banging his right foot on the ground in pain.

“It’s an excruciating pain, but I think any time you look at your ankle and it’s in a different direction, you’re probably not going to try to get up,” Griffin recalled after the game. “I was just trying to make sure I wasn’t doing any more damage to it, so I stayed there and waited for the trainers to come and help me get up and on the cart to get the X-rays.

The Redskins offense shined on Sunday, despite serious injuries to Robert Griffin III and DeSean Jackson. The Washington Post's Gene Wang and Dan Steinberg discuss the impact these injuries will have and how the team will move forward with Kirk Cousins at the helm. (Meghan Sims/The Washington Post)

Griffin remained on the sideline with medical personnel, including orthopedic surgeon James Andrews, tending to him for roughly five minutes.

The play looked eerily similar to the one on Jan. 5, 2013, in the playoffs against Seattle, when Griffin rolled to his right, threw across his body and injured his right knee when his right cleat got stuck in the playing surface. But this time, Griffin hurt the ankle on his other leg.

Before Griffin had even been helped off the ground, Cousins entered the game and threw a 20-yard touchdown pass to fullback Darrel Young. With the home crowd in a frenzy, cheerleaders dancing on the field and the band playing “Hail to the Redskins,” Griffin continued to be examined and shortly after was helped onto the cart.

With pain etched on his face and a hefty brace on his left foot and leg, Griffin rode off on the cart as fans chanted, “RGIII! RGIII!” The quarterback waved to the fans as he rode off into the tunnel.

“We’re sick about Robert,” Gruden said. “He started the game hot and had some great energy. It’s very unfortunate. He put a lot of effort, time and mental anguish to get ready for this year and have a bounce-back year. Things happen in pro football. Starters get hurt and backups have to come in. This is an extreme circumstance, but Kirk is more than ready to take over.”

Said left tackle Trent Williams, “It’s obviously very disappointing. Any time you have a player get hurt, it’s only 53 of us, so we’re very close. You never want to see anybody get hurt, especially the franchise, which Robert is. . . . But he’ll be back. I’m fully confident he’ll get back to do what it takes to help the team.”

As Griffin received additional testing, things hummed along for Griffin’s teammates on the field. The defense recorded the second of six three-and-outs.

After a stagnant first full possession for Cousins and the offense, that unit began clicking again and opened the second quarter with a one-yard touchdown run from Morris to cap a seven-play, 66-yard scoring drive.

Turning frequently to tight end Paul, who took on a larger role with Jordan Reed sidelined, and wide receiver Andre Roberts, who stepped up with Jackson out, Cousins directed an offensive attack that generated 449 yards and 32 first downs while dominating time of possession, 39:01 to 20:59.

Cousins completed 22 of 33 passes (including his first 12 attempts) for 250 yards, two touchdowns and no interceptions.

“I was glad we were able to get the win today,” Cousins said. “I was able to help us get there. That’s the job I’ve been in now for three seasons. Just trying to make the most of every opportunity I get.”

Morris rushed for another touchdown later in the second quarter, and early in the fourth, Paul hauled in a two-yard touchdown pass (the second of his career). Rookie Silas Redd relieved Morris late in the game and scored on a 14-yard run.

Despite being listed as questionable for the game because of a groin injury and deferring all kickoff duties to punter Tress Way, place kicker Kai Forbath made a pair of field goals.

Jacksonville, which ranked 31st in the league on offense last season, managed just eight first downs and 148 yards (25 rushing) and fell to 0-2.