PARIS—Bjorn Fratangelo was in danger of getting kicked out of high school for missing too many days, but it isn’t like he was down at the river fishing, up at the mall smoking cigarettes, or somewhere between the two, just texting his friends, “Bro. Wass up?”

Fratangelo’s poor attendance record was the result of all the time he spent practicing and playing tennis, a game at which he’s pretty good. Good enough to have won the French Open boys' junior title today, with a whistling clean and gritty, disciplined victory over the No. 14 seed, Dominic Thiem. Showing equally impressive amounts of firepower and poise, Fratangelo survived a compelling marathon, 3-6, 6-3, 8-6.

“Bjorn got calmer as the match went on," said Jay Berger, head of men’s tennis at the USTA. "That’s the sign of a really good player, the ability to hang in there whatever it takes, then step up and finish it off.”

That’s “really good player” as in Bjorn Borg, right? (And I thought you’d never ask!) Fratangelo was indeed named after the Swedish star, who was an “idol” in the eyes of Mario Fratangelo, Bjorn’s father and primary coach. Bearing the name has been a bit of a mixed blessing for Bjorn, even if it provides journalists with a no-brainer opening paragraph. “You know, if there's ever articles about me or stuff about me, that's usually how they start it, out that I was named after Borg. But, um, besides that, it's just my name. That's about it. But thank God I didn’t end up hating this sport. Let’s put it that way. Otherwise I’d end up having to live with that name.”

Fratangelo, 17, was born in Pittsburgh (and remains a fan of the NFL's Steelers), which also provided the tour with Don Johnson and Tom Mercer. But a combination of his rapidly developing game and the policy at Barron Collier High School demanded he find a better arrangement. “I missed too many days of school. It was a public school, so they weren't really allowing that. That’s when we moved to Naples.”

Fratangelo, who’s technically entering his senior year, completed his junior year taking on-line courses and isn’t sure what he’s going to do for his final year of high school. Now that he’s a junior Grand Slam champion, he might be tempted to go out and consolidate his official ITF junior ranking (he was No. 21 before the French Open); he could even fling himself off the deep end and become a de facto pro, playing Futures and Challenger events. That’s not very likely, tough, because he’s always done things a little differently. For example, one reason his ITF ranking wasn’t higher coming in is because he doesn’t really believe in playing the international junior circuit. In fact, this was his first trip to Europe.

“You know, the whole ITF thing, it can be a grind, which I think in one way is good, because that's what the ATP tour is going to be like," Fratangelo said. "And in other way, you know, to do all that traveling for junior events sometimes, I don't quite see the point. But I play the tournaments that are closer to home." (Which ranges from Carson, CA to Tulsa, OK and points south, including Costa Rica.)

Fratangelo likes clay; he’s won a number of big junior clay-court events. But despite his success here, Fratangelo isn’t even going to bother trying his hand on Wimbledon’s grass. “It’s not my favorite surface. Not that I really played on the Wimbledon grass, but. . . I'm just deciding to play some Futures, to try to get some points and get the ATP rating up. Then I’m playing the hard courts at Kalamazoo (the national junior hard-court championship) and the U.S. Open.”

You certainly can’t blame Fratangelo for the uncertainty he may have about what to do next. That he has the support of the USTA and its coaches and trainers will make it easier to make a decision, because his win here pretty much guarantees that he can count on help. The past week has been a potentially life-altering one, and as confident as he was today, he could not have seen this coming.

“I never won a Grand Slam match before,” he said. “I have only played two others, which are two U.S. Opens, 2009 and 2010. You know, my first expectation coming here was to get through my first round. If I could do that, then, you know, I'm not pleased but—thank God I finally got the first round out of the way.

“After that, each match got better and better. I got more confident. I really like this surface a lot. It suited my game well. It helps my forehand a lot to jump through the court.

“I guess I never looked back. I never got nervous. I was having a blast being here.”

He neglected to add, it sure beat sitting in class.