Joy and despair — opposite emotions, to be sure, but both can bring tears.

Just ask Johnnie Dixon.

Actually, Ohio State quarterback J.T. Barrett did just that. The question came late in last week’s come-from-behind win over Penn State in which Dixon had caught two of Barrett’s four touchdown passes as the Buckeyes rallied from 18 points down to save their big-dream season.

“If you were watching, you could see J.T. look at me and say, ‘Hey boy, you cryin’?’ ” Dixon recalled. “I told him ‘Yeah.’ ”

Dixon was unashamed about it, too, as the Buckeyes turned their attention to Saturday’s game at Iowa.

“I was just so emotional, because I knew where I came from to get to this point, I knew the injuries and the pain I’d had to deal with and get over,” Dixon said. “And being able to have a moment like that, it was just so special to me.”

He also shared the emotion with “P” — his best friend Parris Campbell, who had to leave the game early in the first quarter after suffering a head bump. They have been tight for going on four years and have dealt with the ups and downs that come with trying to secure a prominent role on the big stage for the Buckeyes.

For Dixon, the previous three years had been a grind as he fought through chronic knee pain only to experience a breakthrough this past winter.

“After the game I reminded P, ‘Hey bruh, I almost quit. I really almost gave this up,’” Dixon said. “The feeling was so amazing after that game. The whole night I was just smiling.”

Others shared his glee, including coach Urban Meyer. Four years earlier, he and his staff had staged a major recruiting victory when they talked Dixon, a four-star performer on the Class 7A Florida state champion Dwyer High School out of West Palm Beach, to sign with the Buckeyes over Alabama.

“He comes from that kind of program. He comes from that kind of family. They don't know quit,” Meyer said. “And they know that at some point that rock will break if you keep hitting it.”

In celebration, Meyer summoned Dixon to his office earlier this week, then they got on a speakerphone call with Dixon’s high school coach, Jack Daniels.

“Coach Meyer started out by saying he’s ‘never going to recruit a kid from my high school again because they’re not hard working, they’re not a good teammate, they don’t believe in the team aspect, and they don’t produce,’ ” Daniels said. “And I said, ‘Well, I know you’re not talking about Johnnie Dixon. Maybe his production wasn’t what you wanted from the start, but I know he’s a great teammate and a great kid.’

“Of course he was just pulling my leg. Then he told Johnnie to say hi, and how he’s coming around, making plays, and how he’s extremely happy with him.”

Based on the nearly effortless way Dixon made plays in high school, a natural route-runner, position-gainer, pass-catcher and then sprinter, he was expected to have an immediate impact when he joined the Buckeyes.

Instead, a knee problem that had started when he was rolled up on in a seven-on-seven competition a couple of years earlier, was exacerbated. It happened as an early enrollee the winter of 2014 when he dived into the grind of the Mickey Marotti-directed offseason program.

Surgery on both knees to relieve the chronic tendinitis did not do the trick. Over three years Dixon got to a certain point in almost every workout where the pain would not let him go further, and he would back away.

That brought tears of despair. They came big time as he sat in his locker at the University of Phoenix Stadium last New Year’s Eve. He wasn’t even in uniform that day for the Buckeyes’ 31-0 College Football Playoff semifinal loss to Clemson.

“I was really down,” Dixon said. “Playing football, that’s something I’ve been doing all my life since I was young young. I chipped my tooth playing this game. My first touchdown — I still remember that.

“So the thought of giving it up, I don’t know how I was going to do it and deal with it. I almost made that decision. Sometimes I would just sit up at night and cry, praying on it.”

His friends and fellow Ohio State receivers Campbell and Terry McLaurin urged him to give it one more try. A meeting with Meyer, Marotti, receivers coach Zach Smith and others set the goal. Then he dived again into rehab, grueling daily workouts led by Marotti that attacked more the pain threshold than the pain.

“That’s what we all talked about,” Dixon said. “If you’re going to take one last swing at it, swing as hard as you can.”

Amazingly, one day suddenly his knees felt whole again. He went through spring practices without missing a beat for the first time, and it continued through preseason camp. Then came the game-cracking catch-and-sprint for a touchdown in the season opener against Indiana.

Dixon was back, and his confidence has grown steadily. He has only 13 catches so far, but six have been for touchdowns. He is averaging 25.5 yards per catch.

“I think I can do anything that any receiver in the country can do, some things better,” Dixon said. “I believe I have a high level of play right now, but I can always be better. If you don’t feel like that as an athlete, there’s something wrong with you.”

And now he has proof with what he did in Ohio Stadium last week, that in a big game he can rise to the occasion. So, of course in the aftermath, there were tears.

“Legends are born, careers are made inside that stadium,” Dixon said. “I just knew that I had to make a play for the team. That’s all it was.”