The WBO is the youngest and many would say least prestigious of the recognised boxing administrations. Started in 1988 by disaffected members of the WBA, their first heavyweight title fight was a low-glamour match-up between Francesco Damiani and Johnny du Plooy.
Damiani would KO du Plooy (who became grossly overweight in retirement and died in 2013) in the third round, but his reign ended at the end of a Ray Mercer uppercut and his career ended when beaten by Oliver McCall, a troubled man who upset Lennox Lewis but is best remembered for a tearful breakdown during the rematch.
LISTEN: Nathan Rarere: Why Parker was awarded the win
The WBO has lifted its game since its early days, but then again it was setting the bar pretty low. How low? Well let's just say that in 2001 the organisation did little for its credibility when it twice moved Darrin Morris up its super-middleweight rankings to a high of No 5.
The Mongoose Morris was a decent boxer by all accounts, but he was also dead. He moved from No 7 on the rankings to No 5 post-mortem. Then-WBO president Francisco Varcarcel duly noted the improbability of that feat, saying: "We obviously missed the fact that Darrin was dead. It is regrettable."
British boxer Tyson Fury is still with us, but his cocaine-induced inactivity has led to the vacation of the belt and the opportunity for Parker and Ruiz Jr to fight for it in Auckland last night.
Fury was also WBA heavyweight champ, the oldest and perhaps grandest of the four organisations recognised by the IBHOF. The World Boxing Association was once based in the USA and was known as the NBA. It is now based in Panama City and can no longer be confused with the basketball giant.
The World Boxing Council was formed in Mexico City in 1963, and has 161 'member' countries. The WBC has gained a reputation for being dismissive of its three rivals and extremely friendly with Don King.
The IBF, are you still with us, was formed in New Jersey in 1983 after the head of the United States Boxing Association (USBA), failed in his bid for WBA presidency. It was initially called the USBA-IBF but that was just silly.
The WBO, as mentioned, was also formed out of a dispute between WBA members. This time, a group of mainly Puerto Rican and Dominican members left to form the WBO in San Juan.
The IBF's heavyweight champion is British star Anthony Joshua. The WBO's is now Parker's.
Duco make no secret of the fact they would dearly love their young superstar to fight Joshua in a partially unifying bout that could make a lot of money for a few people.
For that to happen, first Parker had to beat Ruiz Jr.
He did that. Now watch this space in the 'alpha-belt' boxing battle.
