Marcos Maidana

Maidana vs. Kotelnik

On February 2, 2009, the then-WBA Light Welterweight titleholder Andreas Kotelnik beat the then-undefeated Maidana (25-0, 24 knockouts) via controversial split decision, with the judges scoring the fight 115–114, 113–115, 115–113 in Kotelnik's favour.

Maidana vs. Ortiz

Maidana's first fight in the United States was against Victor Ortíz, that took place on June 27, 2009. Maidana was knocked down three times within the first two rounds, but rallied and came back to beat Ortiz for the interim WBA super lightweight title with a sixth-round TKO victory.

Maidana vs. Cayo

After his fight with Ortiz, it was rumoured that Maidana would face British boxer, and WBA super lightweight champion, Amir Khan, who won the title after defeating Andreas Kotelnik. However, Khan opted for Paulie Malignaggi as his next opponent. As a result, Maidana was scheduled to fight on March 27, 2010 against Victor Cayo, whose record, at that time, was 24-0 with 75% of victories coming by way of knockout. Maidana knocked out the undefeated Cayo in the sixth round to retain his interim WBA super lightweight title and improve his record to 28-1, with 27 knockouts.

Maidana vs. Corley

After failing to secure a fight with Timothy Bradley, Maidana fought and defeated DeMarcus Corley in August 2010. Despite knocking Corley down in the 7th round, Maidana had to go the distance for only the third time in his career, eventually securing the victory via unanimous decision (117–110, 117–110, 115–112).

Maidana vs. Khan

Before his fight with Corley, Maidana accused Khan and trainer Freddie Roach of "hypocrisy" and called out Khan in an interview:

On September 15, ESPN revealed that both fighters had agreed to fight on December 11 at Mandalay Bay, Las Vegas.

Khan dominated the fight early and knocked down Maidana in the 1st round with a left hook to the liver, but had to withstand a furious barrage by Maidana in round 10, and continually backed up during rounds 11 and 12. Maidana was unable to finish Khan however, who went on to win the fight by unanimous decision (114-111, 114-111, 113-112). The fight was awarded the Boxing Writers Association of America Award for Fight of the Year.

Maidana vs. Morales

In the first round against Érik Morales, Maidana came out with ferocity as expected and proceeded to batter his older opponent around the ring. He landed multiple power punches, including an uppercut that opened a huge swelling over Morales' left eye which worsened over the course of the fight, and when the Mexican walked back to his corner having taken a large amount of punishment in the opening three minutes most observers felt their predictions were being fulfilled. The one-sided nature of the bout continued for the next couple of rounds, but then at the end of the third round Morales begin to fight back and landed a hard combination to the head of Maidana and the tide began to turn.

From the fourth round onwards and although he was effectively fighting with one eye, Morales gave as good as he got and was landing the cleaner more effective shots, albeit occasionally being swarmed by the sheer number of punches being landed in return by the relentless Maidana. The fight became a see-saw affair and then, in the eighth round, Morales hit Maidana with a huge left hook that almost stopped the Argentinian. The next couple of rounds continued in this fashion, with Maidana using his strength and stamina to bully Morales and the Mexican using his sharper punching and ring intelligence to land effective counters and combinations. The fight was fast turning into a modern classic.

In the "championship rounds" (the eleventh and twelfth), Morales seemed to tire and Maidana took advantage, overwhelming him with his strength and punishing the ageing warrior continually to the head and body. Maidana finished the fight much the stronger of the two and his late surge gave him the win on the scorecards, 116–112 twice with the third judge scoring the fight a draw, 114–114.

Maidana was scheduled to defend his title Aug. 27 against Robert Guerrero, but Guerrero suffered a shoulder injury less than two weeks before the fight. Maidana's fought Petr Petrov of Russia on Sept. 23 instead, winning by fourth-round knockout.

Welterweight

On February 25, 2012 Maidana moved up to welterweight and fought Devon Alexander who was also moving up in weight. Maidana clearly seemed uncomfortable in his first fight at the new weight as Alexander dominated the fight and went on to win a lopsided unanimous decision. In his first fight following the Alexander loss, Maidana defeated Jesus Soto Karass on September 15, 2012 by eighth-round TKO in a back-and-forth slugfest.

Maidana then fought the largely unknown Angel Martinez on December 12, 2012. Maidana won the fight by KO in the third round.

Maidana vs. Lopez

Maidana scored a TKO over welterweight contender Josesito Lopez in the sixth round of a June 9, 2013 fight. Maidana had injured his hip in the second round and Lopez capitalized tagging his opponent with hard shots. Maidana was able to reverse the tide and hurt Lopez with an overhand right in the sixth round that dropped him to the canvas. Lopez later said that Maidana is the hardest puncher he ever faced.

Maidana vs. Broner

On December 14, 2013, Marcos Maidana defeated the heavily favored Adrien Broner after 12 rounds via unanimous decision to win the WBA Welterweight title. Maidana dropped the previously unbeaten Broner in the second and eighth rounds and won by comfortable margins on all three judges scorecards, 115–110, 116–109, 117–109. Maidana was a 3/1 underdog entering this fight. He had now won four consecutive fights under the tutelage of boxing trainer Robert Garcia.

Maidana vs. Mayweather Jr.

The pinnacle of Maidana's career came in 2014, when he secured a fight against undefeated multiple-time world champion Floyd Mayweather Jr., in an event billed as The Moment. The bout was held on May 3 at MGM Grand Garden Arena, and aired on Showtime pay-per-view. Maidana would go on to lose his WBA welterweight title via majority decision after a competitive fight, in which Maidana spent a significant portion using aggression, constant pressure, and rough-house tactics against Mayweather. By the end, one judge scored the bout a draw at 114–114, while the other two scored it 117–111 and 116–112 in favor of Mayweather. The fight was viewed as close by some ringside observers, fans and experts alike, and the two wide scorecards were deemed controversial given the competitive nature of the fight.

Maidana vs. Mayweather Jr. II

A rematch with Mayweather was later confirmed, with the bout taking place on September 13, 2014 at the MGM Grand Garden Arena, with Mayweather's WBA (Super), WBC and The Ring welterweight titles at stake, as well as Mayweather's WBC light middleweight title. Mayweather won the fairly one sided affair via unanimous decision, with scores of 115-112, 116-111 and 116-111. Maidana hurt Mayweather greatly at the end of the third round; he drew Floyd in with a jab that he attempted to counter with a straight right hand but in the process moved his head into a return counter by Maidana in the form of an overhand right that sent Floyd back into the ropes, just as the bell rang to end the round. Despite this, Maidana had little success in the bout.

Retirement

On August 9, 2016, Maidana officially announced his retirement from professional boxing at the age of 33, allegedly moving into an advisory role. Maidana wrote in a letter addressed to boxing friends on social media: "After a long time out of the ring and after giving it a lot of thought since my last fight I've decided to hang up the gloves for good. Probably my decision would not surprise much as I had given hints of it in the last few months. But at this time I am making it official." Maidana finished with a career record of 35 wins in 40 fights, 31 wins coming by way of knockout and 5 decision losses.

Personal life

Maidana said that he would support his son being a boxer if his son wanted to become a boxer, but Maidana said that he would not want his son to become a boxer.

Maidana said that he is of indigenous descent.

Maidana said that he liked the "Chino" nickname, and Maidana said that he was not going to change it.