Early career Lopez signed with
Top Rank in October 2016, and made his debut on the undercard of the
Manny Pacquiao vs. Jessie Vargas fight in November of the same year. After compiling a perfect 10–0 record, he announced himself to the world stage in December 2018 by beating veteran Mason Menard with a knockout of the year candidate. In his next fight, Lopez, already ranked #9 by the WBA, #11 by the WBC and #10 by the WBO, faced another boxing veteran in
Diego Magdaleno, which ended in another brutal knockout win for Lopez. He attracted some controversy after his exuberant celebration with Magdaleno still down on the canvas. Lopez's winning streak continued, improving to 13–0 with a fifth-round knockout victory against former world title challenger
Edis Tatli on April 20, 2019, on the undercard of
Terence Crawford vs.
Amir Khan at
Madison Square Garden, New York City.
IBF lightweight champion Lopez vs. Nakatani On July 19, 2019, Lopez who was ranked #4 by the
IBF at the time, faced undefeated
Masayoshi Nakatani, who was ranked #3, in a final eliminator for the IBF world lightweight title. In the fourth round, Lopez knocked Nakatani down with his right hand, but the referee ruled it a slip. The fight marked the first time Lopez had gone 12 rounds in his career, and he was awarded a
unanimous decision victory with scores of 118–110, 118–110, 119–109, setting up a clash with IBF champion
Richard Commey.
Lopez vs. Commey On December 14, 2019, Lopez challenged the IBF lightweight champion
Richard Commey. Lopez won the IBF title in spectacular fashion after connecting on Commey with a big right hand, and finishing him with a second-round technical knockout. After the conclusion of the fight, Lopez was joined in the ring by fellow lightweight champion
Vasiliy Lomachenko, with whom he took a photo with. When asked about his plans for his next fight and a possible unification bout with Lomachenko, Lopez replied, "You guys know who I want," referring to Lomachenko without explicitly naming him.
Unified lightweight champion Lopez vs. Lomachenko In September 2020, Lopez agreed to fight unified WBA (Super), WBO, and
The Ring champion,
Vasiliy Lomachenko, on October 17 at the
MGM Grand in
Las Vegas. It was the first major fight since the outbreak of the
COVID-19 pandemic. With no live audience, Lopez defied the odds with a stunning upset victory as he beat the highly-regarded Ukrainian by unanimous decision to unify the lightweight division and maintain his unbeaten record, with the judges' scorecards reading 116–112, 117–111 and 119–109. The first seven rounds saw Lopez staying behind his jab and going to the body, with his opponent offering very little in response. In the second half, Lomachenko started coming out more offensively, landing more punches. However, in the final round, Lopez landed 50 of 98 punches thrown (51%), the most an opponent has landed on Lomachenko in a round. According to CompuBox stats, Lomachenko landed 141 of 321 thrown (44%), while Lopez landed 183 of 659 thrown (28%). Lopez declined to give Lomachenko a rematch, explaining that “everybody [in Lomachenko’s camp] was being a dick to me, my father. He [Lomachenko] didn’t want to put a rematch clause in our contract." In the wake of his victory, Lopez asserted that he is the
undisputed lightweight champion, despite not holding the WBC belt. However, the claim was contested by many boxing analysts and fans, as the 'Franchise' version of the WBC title won by Lopez against Lomachenko lacks recognition from a large portion of the boxing community, including
Devin Haney, recognized by others as the holder of the legitimate WBC lightweight title.
Lopez vs. Kambosos Jr. Lopez's first defense of his unified lightweight championship had been scheduled for June 5, 2021, against undefeated contender
George Kambosos Jr., before being delayed multiple times due to complications involving Lopez testing positive for
COVID-19, and disputes over the venue of the fight. The fight had gone to purse bids which was won by
Triller with a winning bid of over US$6 million, leading to a fallout between Lopez and
Bob Arum, head promoter at
Top Rank. On October 6, it transpired that the IBF had found Triller in
default of its contract obligation to stage the fight, and that its rights would be awarded to the second highest bidder,
Eddie Hearn's Matchroom, meaning that the fight will be shown live exclusively on the streaming service
DAZN. Despite Kambosos entering the bout as a 13 to 1 pre-fight betting underdog, he knocked down the champion in the first round of the fight. Despite returning the favor by knocking down Kambosos in the tenth round, Lopez ultimately lost the bout via split decision. One judge scored the bout 114–113 to Lopez, while the other two judges scored it 115–112 and 115–111 for Kambosos Jr.
Light welterweight Lopez vs. Campa, Martin For Lopez's eighteenth professional fight, he moved up to the
light welterweight division. In his first bout at the weight class on August 13, 2022, he successfully rebounded from his loss against Kambosos by defeating Pedro Campa via seventh-round technical knockout after a dominant performance. Lopez would return on December 10, 2022, against
European light welterweight champion
Sandor Martín in his second bout at the 140 lb limit. The first round saw an aggressive start from Lopez, where Martin busted his nose during a clash of heads. Martin was able to knock Lopez down in the second round with a check right hook. The fight was competitive, resulting in a split decision after the final bell, with judges' scorecards of 97–92 and 96–93 in Lopez's favor, and 95–94 in Martin's favor. Lopez was caught on camera in the ring post-fight candidly questioning his team: "Do I still got it?"
WBO and The Ring light welterweight champion Lopez vs. Taylor On April 8, 2023, it was officially announced that Lopez would attempt to become a two-division world champion and challenge undefeated WBO and
The Ring light welterweight champion
Josh Taylor on June 10 at the
Hulu Theater in New York City. He won the fight by unanimous decision, becoming a 2 division world champion. On June 12, Lopez announced his retirement from boxing.
Lopez vs. Ortiz On February 8, 2024 in Las Vegas, Lopez defeated
Jamaine Ortiz by unanimous decision and made the first successful defence of WBO light welterweight title.
Lopez vs. Claggett Lopez made the second defense of his title against
Steve Claggett at
James L. Knight Center in Miami, FL on June 29, 2024. Winning on a unanimous points decision.
Lopez vs. Barboza Jr. In December 2024, it was announced that Lopez would make the third defense of his WBO junior welterweight title against former IBF champion
Subriel Matías on March 15, 2025. The fight ultimately did not materialize however, with Lopez expressing dissatisfaction with his own promoter
Top Rank for attempting to make the Lopez–Matías fight: "It's a shame that Top Rank has to put me with a guy, one offer, with Subriel Matías, who has no [commercial] value." Lopez instead expressed interest in facing
Jaron Ennis or
Richardson Hitchins, though those fights did not materialize either, ultimately returning to the ring on
Turki Alalshikh's
Times Square card as part of
Riyadh Season on May 2, 2025, defending his WBO and
The Ring titles against WBO
interim champion Arnold Barboza Jr. Lopez comprehensively outboxed Barboza Jr., recording his fourth consecutive unanimous decision victory. The official judges' scorecards read 116–112 twice and 118–110, with Lopez landing 127 of 574 punches. Barboza couldn't keep pace, with only 71 punches landed of 426 thrown. In his post-fight interview, Lopez again expressed interest in fighting unified
welterweight champion Jaron Ennis, referring to Ennis by his moniker "Boots": "I want to see Boots. I'm
Dora the Explorer and I'm looking for Boots." The undefeated Stevenson (24-0, 11 KOs) and Lopez had both consistently alluded in recent weeks that they were negotiating to fight each other next, with the two appearing together on "Inside The Ring" in September to promote the potential matchup. Stevenson, ranked No. 8 on ''The Ring's''
pound-for-pound list, expressed his intentions to move up in weight without a tune-up fight: "Pound-for-pound, I'm going to beat the man at 140, get the Ring Magazine belt, and laugh at all who doubted. No tune ups, no fights to get comfortable at the weight — just big balls and big dreams." The fight was expected to be part of a
Premier Boxing Champions card and backed by Turki Alalshikh. Both expressed excitement for the matchup during the
Crawford-Álvarez fight in Las Vegas. Stevenson was aiming to capture a fourth division title. While the
Barclays Center in Brooklyn was the likely venue for the bout, it was stated that Stevenson’s camp preferred
Madison Square Garden to avoid Lopez's hometown advantage. On November 5, it was reported that negotiations were advancing positively regarding the fight. A potential date was identified as January 31, which would strategically place the event between the
NFL conference championship games and the
Super Bowl, potentially increasing its visibility and viewership. On December 1, the fight was announced to take place on January 31 in New York, as part of "The Ring VI", exclusively on
DAZN. The fight would see Lopez defending his WBO junior welterweight title. Stevenson was aiming to become a four-division champion. On December 9, Madison Square Garden was confirmed as the venue. Stevenson was a heavy -350 favourite while Lopez was entering as a +250 underdog. According to Lopez, there was no rematch clause in the contract. Lopez revealed that his training focused on adjusting his fighting style to manage range and distance effectively. He described Stevenson as “one-of-one”, a unique and formidable opponent. == Personal life ==