It happened like this: in the mid 1960s Bill Bowerman's thoughts and ideas for racing flats were being sent to Japan, where Onitsuka Rubber was transforming them into a shoe that would be used in the upcoming 1968 Olympic Games, and of course be sold to Americans by Blue Ribbon Sports. The early name for the model was The Aztec, an homage to host Mexico City. adidas beat them to the punch coming out with the Azteca Gold first, and sent a letter threatening litigation if Onitsuka came out with that Aztec model name. So the last second name change went to Cortez, or as Bowerman put it, "that Spaniard who kicked the shit out of the Aztecs."
As the Onitsuka/Blue Ribbon Sports partnership began to strain, Phil Knight went about creating his own brand. He started with a football/soccer cleat that was made in Mexico by Canada Shoes, and then an order from Nippon Rubber in Japan that included tennis, wrestling, basketball shoes, and 6,000 pairs of Nike branded Cortez, the first pairs of non-Tiger Cortez. Onitsuka eventually found out that Blue Ribbon Sports was making some of their own shoes, (when caught, Shoji Kitami from Onitsuka Rubber wanted to know what this "Mike" brand is all about - he thought the cursive N was an M) and the Onitsuka/Blue Ribbon Sports partnership was all but over.
Stock of Tiger shoes from Onitsuka Rubber quickly dwindled at Blue Ribbon warehouses, and the Nike brand had to be ramped up to meet the orders for Cortez. Blue Ribbon also had to begin telling their customers that Nike is just as good, if not better than the Tiger shoes Blue Ribbon had been promoting mere weeks earlier. And just as Blue Ribbon was getting customers to switch to Nike, delays forced Phil Knight to pay $145,000 (over $800,000 in 2013 money) to air freight another shipment of Nike Cortez into the United States from Asia so Blue Ribbon could fulfill its orders by agreed upon dates.
In 1974 the whole thing ended up in court, and Blue Ribbon Sports went its way with its Nike Cortez and Onitsuka went their way, also with the Cortez-but changing the name of the model to the Corsair.