When Trinidad Sr. announced his decision to turn his son into a professional boxer rather than wait for the 1992 Barcelona Olympics, he was met with skepticism and criticism from Puerto Rico's top boxing experts.
Trinidad Jr, however, proved them wrong quickly by burying opponent after opponent to the canvas. Among Trinidad's victims was Jake Rodriguez, a fellow Puerto Rican and former Jr. Welterweight champion of the world, who was the only one to last 10 rounds with him during this period.
In 1993, Trinidad travelled to San Diego, California and defeated the crafty defending world Welterweight champion Maurice Blocker in 2 rounds , in a fight televised by Showtime. It was the beginning of a long lasting friendship between the new champion and the cable network.
Defending this title, he beat former and future world champions Hector 'Macho' Camacho, Freddie Pendleton, and 'Yori Boy' Campas among others. He kept defending the title until he was able to sign for an unification bout with the other world Welterweight champ, Oscar De La Hoya. During all of that, Trinidad changed alliegances from Showtime to HBO.
The highly anticipated bout between the 2 Welterweight champions took place September 18, 1999 at the Mandalay Bay Hotel hotel in Las Vegas. It was nicknamed The Fight Of The Millennium. It was extremely close for 8 rounds and the 3 judges had scored the fight a draw, but De La Hoya gave it away by thinking he'd won all 8 rounds and relaxing the next 4 rounds, while Trinidad kept attacking to secure a split decision and a win in his biggest fight.After the fight, he was the object of the greatest welcoming in the history of Puerto Rico's Luis Munoz Marin International Airport.
After leaving the Welterweight world championships vacant, Trinidad moved in weight to challenge World Jr Middleweight champion David Reid, a Las Vegas talent, again at the Mandalay Bay. Trinidad was knocked down in the 3rd, but proceeded to beat Reid, dropping him 5 times and winning a unanimous decision. Next, he unified the title vs the other world champion, the extremely brave and murderous power-puncher Fernando Vargas of Oxnard, California. This bout was for the ages and Trinidad had to rise from the canvas in round 4 after a sensational start that saw him drop the Mexican warrior twice in round one, but he prevailed by dropping Vargas again 3 times in round 12, the last knockdown after which the fight was stopped. To Vargas' credit, he was true to his word: He had said he'd rather prove he is a real Mexican warrior by finishing off his feet if that was to be his fate than relax and back away the way De La Hoya did, and he did prove it. After Trinidad left the division, he came back and regained the world title.
Trinidad once again moved up in weight, lured by Don King's Middleweight unification tournament and he beat William Joppy by a knockout in 5 rounds to become world Middleweight champion. His unification bout with the other world champ, Bernard Hopkins of Philadelphia, originally scheduled for September 15 2001 at the Madison Square Garden had to be postponed because of the September 11 Terrorist attacks. It was fought, however , two weeks later, on September 29, and Trinidad had to taste the sour taste of defeat this time, losing for the first time after bravely trying to overcome the strong and physically more mature Hopkins, who then became the undisputed world champion in the division.
Trinidad's fans in Puerto Rico proved how much they really loved him by mounting another large welcoming at the airport after his defeat.
After beating former Middleweight world champ Hassine Cherifi of France by ko in 4 rounds in San Juan, Trinidad shockingly announced his retirement, leaving the sport of boxing with a record of 41 wins, only 1 defeat, and 34 wins by knockout. He is currently trying to reconcile with his wife Sharon, after a scandal broke out where it was discovered he had a baby girl with a TV model that he had an affair with. He has committed to pay the child's support and help raise her along with his 2 other daughters with Sharon.