DETROIT — Clutching the game ball, an excited Jameson Williams entered the post-game press conference room at Ford Field for the first time in his career Sunday night with a big grin on his face.

“I’ve never done this before,” the third-year Detroit Lions receiver told the press room.

Williams was in the spotlight after posting a personal-best 121 receiving yards on five receptions in Detroit’s thrilling 26-20 overtime win over the Los Angeles Rams.

His previous best was 69 yards at Dallas in Week 17 of last season.

“This is just Game 1. I put a lot of work into it. I expected to have a big game. I personally expect to have a big game,” Williams said. “I think this is just big for the world because it’s my first, but I plan on playing a lot more. I don’t expect this to be the best game of my career. I expect this to just be the beginning of me.”

Williams, the No. 12 pick in 2022, flew into the end zone to celebrate beating his defender along the left sideline for a stunning 52-yard touchdown on a deep pass from Jared Goff at 10:37 of the third quarter.

The touchdown was the longest receiving TD of his career and his second-longest reception, behind a 64-yarder last season with Dallas. Coach Dan Campbell said he thinks the former Alabama star can step it up and continue to grow after his big day in the season opener.

“He showed up. I mean, that was a great game to be able to catch a couple and get through it. And the best part about it was he didn’t even play his best ball,” Campbell said. “There’s still so much to clean up, but it also shows how much work he’s put in, and he’s improving, and he’s an improved player, and he wants it, and he keeps working at it. And he just keeps, he keeps taking those steps.”

Williams’ NFL career didn’t get off to an expected start, due to an ACL injury and a gambling suspension during his first two seasons. But after an impressive summer, he’s earned the trust of Lions offensive coordinator Ben Johnson and the coaching staff, who were comfortable with giving him a bigger role in the system.

His 121 receiving yards on Sunday were the third-most receiving yards in a season opener by a Lions player since 2000, trailing Hall of Famer Calvin Johnson in 2015 (164) and TJ Hockenson in 2019 (131), but he’s not satisfied with that one game. And he’s never lacked confidence.

“I felt like an NFL star, too, but now you see it. I don’t look at this as just another game,” Williams said. “It’s just the beginning. It’s the first game of the season. I’ve got a lot more in me.”

For the Lions, beating the Rams marked their first overtime victory since 2016. They won the toss and received the ball, then ran on seven of their eight plays, wearing down the Rams defense with their strong ground attack. Running back David Montgomery narrowly sealed the victory with a 1-yard rushing score.

The Lions ultimately needed overtime after blowing a 14-point lead, and All-Pro wide receiver Amon-Ra St. Brown was limited to three receptions for 13 yards. But Detroit was able to pull out the win after shaking off some early rust (most starters had rested the entire preseason) and Williams picked up the slack.

Williams said Sunday’s match was the first he had experienced in his active career and that he would not soon forget the experience and emotions.

“I’ve never been given a game ball, not at Bama, not anywhere,” Williams said as he stared at the ball. “I’m not going to lie. This might not get out of my hands. I might sleep like this.”

Even with the win, the Lions (1-0) expect a cleaner showing in Week 2, when they return to Ford Field on Sept. 15 to play the Tampa Bay Buccaneers.

“There were definitely things that were below our standard,” said Goff, who went 10-for-28 with 217 yards while throwing a touchdown and a pick. “But yeah, some of the operational stuff is ultimately my job and was good enough to get a win, but not good enough to pass our standard.”