Seth Mitchell, right, stayed patient to beat Johnathon Banks by unanimous decision Saturday, avenging his only career loss in November. (Al Bello/GETTY IMAGES)

Seth Mitchell heard the chorus of boos throughout his fight Saturday night at Barclays Center. Impatient spectators were voicing their displeasure about the deliberate pace, imploring the Brandywine heavyweight to swing freely and pursue a knockout against Johnathon Banks.

Mitchell instead stayed away from the aggressive, punishing style that delighted fans in previous bouts and simply outworked his opponent for 12 rounds. The result was a victory via unanimous decision that redressed the only loss of his career seven months ago to Banks and put him back in the conversation as among the most promising Americans in the division.

Judges scored the fight 117-109, 115-112 and 114-112 as Mitchell reclaimed the North American Boxing Organization and World Boxing Council International belts he had lost to Banks in the first meeting.

“I believe I showed that I’m not only a puncher and a brawler, but if I need to box and win a fight, I can do that,” Mitchell said.

From the outset, Mitchell clearly was paying attention to defense and picking his punches wisely. Rarely was he out of position or lunging at Banks, who won their first fight on Nov. 17 with a second-round knockout when Mitchell got careless with his form and left himself unprotected.

This time Mitchell (26-1-1, 19 knockouts) made sure to keep his hands up, and Banks rarely was able to get his punches to the target. The only bit of trouble Mitchell encountered came in the third round, when Banks (29-2-1, 19 KOs) trapped the former All-Met football player from Gwynn Park High on the ropes and began landing repeatedly.

Dazed from the punishment, Mitchell survived when the bell sounded to end the round. Mitchell thereafter was much more active, winning rounds thanks to volume over power. His jab was working especially well, and Mitchell stuck with it for the balance of the match.

Mitchell threw 417 punches to 261 for Banks, including nearly twice as many jabs. He also threw and connected on more power punches.

“I definitely would say my jab was a big key to this fight,” Mitchell said. “Just being patient, and even when I was catching him, not getting reckless and not lunging and reaching.”

Mitchell indicated during the post-fight news conference there would not be a trilogy because no rematch clause was in place this time. A rematch clause was part of the first fight, allowing Mitchell the opportunity for redemption in what turned out to be the longest fight of his career. His previous long fight lasted eight rounds.

Mitchell is set to take several weeks off from boxing before beginning to plan his next move.

“No more Johnathon Banks,” said Sharif Salim, Mitchell’s manager. “I’m very happy [Mitchell] got his 12 rounds in. He worked so very hard. We had two distinct camps. Because we had a seven-month layoff, we’re looking at September to come back. The opponent we don’t know.”