“When I first heard about the decision, I was speechless,” said Sonny Vaccaro. Speechless as in he never thought this day would come.

Vaccaro is the former sneaker marketer turned anti-N.C.A.A. crusader, and he was talking about Friday’s decision in the O’Bannon case — the one in which Judge Claudia Wilken ruled that the principle of amateurism is not a legal justification for business practices that violate the nation’s antitrust laws.

Though he is not a lawyer, Vaccaro is as responsible for the O’Bannon case as anyone. (Disclosure: One of the O’Bannon lawyers works for same law firm as my wife. She has no involvement in the case.)

Vaccaro first got the idea for the lawsuit in the late 1990s, around the time that ESPN bought Classic Sports Network for $175 million. ESPN Classic, as it was renamed, replays games from the past, many of which involve college teams. The players in those games have long since left college, yet they have no rights to their names and likenesses, just as had been the case when they were in school.

How, wondered Vaccaro, could that possibly be O.K.?

Vaccaro is probably best known for coming up with the idea of the “sneaker contract” during his heyday as a marketer for Nike. That’s a deal in which a college coach receives payment for having his team wear a particular brand of sneakers. In the 1980s, still with Nike, he took the idea a step further, paying a university to have all its athletes wear the same brand. There is not much question that Vaccaro helped fuel the commercialization of college sports. Though, as he likes to remind people, “the schools could have turned the money down. They never did.”

In 2007, Vaccaro quit his final job in the sneaker industry — he was at Reebok at the time — to devote his time to fighting the N.C.A.A., an organization he had come to loathe. He began going around the country making anti-N.C.A.A. speeches at universities. Five years ago, while in Washington to make a speech at Howard University, he had dinner with a lawyer friend and laid out his idea of bringing a lawsuit revolving around the names and likenesses of former college athletes. Before long, he was put in touch with Michael Hausfeld, a plaintiffs’ lawyer who was looking for a high-profile case to run with.

And one other thing: He found Ed O’Bannon, the former U.C.L.A. basketball star who became the lead plaintiff. Or, rather, O’Bannon called Vaccaro after seeing an avatar, clearly based on himself, in a video game, asking if he had any recourse. Vaccaro, in turn, put O’Bannon together with Hausfeld. And the rest, as they say, is history.

In the cool light of day, Judge Wilken’s decision does not appear likely to radically reshape college sports. The relief she granted the plaintiffs is likely to put some money into the pockets of athletes who play big-time football or men’s basketball. But it is certainly not going to make anybody rich, and the average fan won’t even notice the difference. It is not like the kind of change that took place when major league baseball players gained the right to become free agents in the 1970s. For instance, she ruled that players still won’t be able to endorse products for money. In so ruling, she bought into one of the N.C.A.A.’s core views — namely that college athletes need to be protected from “commercial exploitation.”

What is radical about her decision — and what could pave the way for further changes in other lawsuits — was her dismantling of the various rationales the N.C.A.A. has put forth over the years as its justification for insisting on amateurism as the bedrock of college athletics. Assuming her decision stands up on appeal, the N.C.A.A. will lose its ability to argue that amateurism is so noble an ideal that, in and of itself, it justifies anticompetitive behavior.

“Do I wish the decision had gone further?” Vaccaro said on Monday. “Sure. It vindicated people like me, who have been voices in the wilderness for so long.”

“We have exposed them,” said Hausfeld. “We have gotten rid of their implicit immunity from the antitrust laws.”

In March, another antitrust suit was filed against the N.C.A.A., by Jeffrey Kessler, a lawyer best known in the sports world for bringing the suit that gained free agency for professional football players.

Kessler’s suit is much more ambitious than O’Bannon’s. He is arguing that the “matrix of restrictions” (as he put it to me) that prevent universities from deciding how to value and compensate players is anticompetitive and violates the antitrust laws.

Thus does O’Bannon now pass the baton to Kessler, as the N.C.A.A.’s critics begin the next leg of this race.