Mayweather's defection opened the flood gates that could reshape the televised boxing world.
For the past several decades, HBO has become synonymous with boxing on cable television. Their groundbreaking attention to the sport drew in countless new fans and spawned several recurring and highly successful programs.
This helped not only to grow the sport but also to showcase all sorts of talent, old and new, to millions of viewers.
The most famous of which are probably still their flagship shows—World Championship Boxing and Boxing After Dark.
The former generally showcases established fighters and gives the fans a break from shelling out pay-per-view cash to see high-profile matchups.
Even so, a lot of the excitement over the years has come from Boxing After Dark, which has helped launch the careers of many a fighter, including the late great Arturo Gatti, as well as Erik Morales, Marco Antonio Barrera and Miguel Cotto.
Even with Showtime emerging as their cable boxing rivals over the years, it was clear that HBO dominated the sport.
But developments in recent weeks have not only shaken the world of boxing, but they've also completely rearranged the balance of power.
There was a time when both of the sport's two biggest stars—Floyd Mayweather and Manny Pacquiao—were exclusive promotional property of HBO.
Their PPVs were mega-events and drew in both the fans and the dollars to keep HBO on top of the boxing game.
But then, in February, Floyd Mayweather Jr. announced a six-fight mega-deal with rival Showtime, spurning the network that has been his home for most of his boxing career and apparently setting off a chain of events that culminated in HBO severing all ties with Golden Boy Promotions earlier this week.
Mayweather, whose past several fights have been promoted by Golden Boy, does not have a formal contract with the company. But his relationship is well known.
He became the most high-profile fighter associated with Golden Boy to defect to Showtime in recent months, joining Saul "Canelo" Alvarez, Danny Garcia and Amir Khan.
And apparently that's enough for HBO to pull the plug completely on doing business with Oscar De La Hoya's company in a move that clearly leaves the network as the big loser.
Golden Boy Promotions' stable of fighters is the deepest group in the sport from top to bottom. It includes rising stars—Adrien Broner, Keith Thurman and Gary Russell Jr.—and a deep roster of veterans, including Bernard Hopkins and Abner Mares.
Essentially what HBO has done here is cede these boxers to Showtime without so much as a fight. It's true that many of them have previously appeared on the rival network, but without HBO even attempting to compete for their services, this provides a major advantage.
It leaves HBO not only without Floyd Mayweather but also without the names most prominently mentioned as his potential successor at the top of the PPV food chain. It also leaves HBO primarily with fighters from Golden Boy's rival Top Rank.
Granted, that's a roster that includes Manny Pacquiao, Juan Manuel Marquez, Timothy Bradley, Nonito Donaire, Brandon Rios, Julio Cesar Chavez Jr., Sergio Martinez and Andre Ward, among others, but it isn't nearly as deep as what fans are used to seeing from HBO.
The spotlight is now shining very bright on Showtime, who will have to decide how much of an investment they wish to make in boxing. Given their massive deal with Floyd Mayweather, it would seem they are willing to invest a lot.
And with the sport's best pound-for-pound fighter in the fold and virtually exclusive access to Golden Boy Promotions' stable of talent, it could just be Showtime that finally emerges from HBO's shadow and claims the crown of cable boxing king.