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It was a fight that no one was sure was going to happen.

Combating failed drug tests, Erik Morales was finally able to step into the ring with Danny Garcia at the first boxing event at the new Barclays Center in Brooklyn on Saturday.

But unfortunately for Morales, it took just four rounds for Garcia to claim victory and retain his WBC and WBA super lightweight titles.

Garcia (25-0) beat Morales for the second time this year, though this one was much easier than the unanimous decision he won from the 36-year-old in Houston on March 24. After a quiet opening two rounds, Garcia began getting the best of Morales with a series of body blows in the third.

Garcia continued firing blows at Morales in the fourth and ended it quickly it for his 16th career knockout. He hit Morales on the right side of the head with a sharp left hook, and climbed the ropes in triumph while awaiting the official announcement.

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"I noticed when I was backing him up with the jabs a little bit and when I was in the pocket hit with a hook one time," Garcia said. "My dad was like, 'You slapped him with a hook.' So the second time I was backing him up. He was trying to take me to the body so I just stood in the pocket. I just turned my whole body. I hit him with a perfect left hook and it landed."

Garcia remained unbeaten despite connecting on 26 percent of his 220 punches thrown. He dominated in power punching, by landing 47-of-91, including nine of his final 13 that led to his latest win.

The 24-year-old Philadelphia native had his second fourth-round knockout in three months. On July 14, he stopped Amir Khan in his first title defense, winning that fight with the same punch that stopped Morales.

"I showed him too much respect in the first fight," Garcia said. "You see the first fight, I thought this fight would be more of a war. I never duck anybody. I fought Khan and no one gave me a chance. Keep lining them up and I'll knock them down."

Morales (52-9) failed two random tests this month because of the diet supplement clenbuterol. He blamed the results on tainted meat, then passed a third test this week and remained on the card.

"Mentally when I found out that his urine was dirty, I was like that's we took the test and I'm not going to do it," Garcia said. "I wanted a fair fight. But when I woke up in the morning, my mom told my dad that I should fight because she had a gut feeling that I would win. So I listened to my mom and I went on with the fight."

Morales, who has held the super bantamweight, featherweight, super featherweight and junior welterweight titles, was fighting for the first time on the East Coast and lost for third time in his last four fights.

"I was prepared to come in and fight but I couldn't get it done," Morales said. "I couldn't get my movement."

Morales said that he wants to fight one more time in his hometown of Tijuana, Mexico, and retire.

The fight marked the return of championship boxing to Brooklyn for the first time in more than 80 years and the card had a Brooklyn feel to it. Leading into the main event was an undercard featuring Brooklyn natives Paulie Malignaggi and Peter Quillan, who each won their fights.

According to Showtime boxing analyst and historian Steve Farhood, these were the first title fights in Brooklyn since Aug. 5, 1931, at Ebbets Field when light-heavyweight champion Maxie Rosenbloom retained his title with a 15-round decision over Jimmy Slattery.

Brooklyn natives Mike Tyson and Zab Judah were in attendance along with Nets point guard Deron Williams.

The crowd was announced at 11,112.

Based on reporting by the Associated Press.

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