[6] He next fought in a WBA title eliminator against the undefeated contender Anthony Peterson, on a HBO Boxing After Dark card.

[8] In the sixth round, a desperate Peterson landed several low blows on Ríos, losing two points in the process.

[9] In the seventh round, Peterson landed low blows once again, prompting the referee to stop the bout and award Ríos a disqualification victory.

Bob Arum stated that if Rios beat Omri Lowther at Cowboys Stadium, Brandon would get a shot to fight against WBC Lightweight Champion Humberto Soto next.

Top Rank promoter Bob Arum dismissed another rematch and suggested to let the two boxers face other fighters first.

[15] Rios and Pacquiao battled for the vacant WBO International Welterweight title on November 23, 2013, at Cotai Arena in Macau.

[19] On November 7, 2015, Rios battled Timothy Bradley for the WBO Welterweight title at the Thomas & Mack Center in Las Vegas, Nevada.

During the emotional post-fight interview, Rios announced his retirement, stating that although he loved the sport, his body was no longer acting the same and that both weight fluctuations and layoffs were affecting his performances.

In his next fight, Rios fought former world titlist Danny Garcia who was ranked #1 by the WBA and #2 by the WBC at welterweight.

[29] In the much anticipated lead up to the Margarito vs. Pacquiao fight at Cowboys Stadium, Ríos made headlines along with Antonio Margarito and Robert García when Elie Seckbach interviewed the three of them and showed the group mocking Manny Pacquiao's trainer Freddie Roach, who has Parkinson's disease.

Elie Seckbach made a video response defending Rios and Margarito, and stated that the media misunderstood their gestures.

García explained that Ríos was "joking around", and that Brandon was also unaware that Roach suffers from Parkinson's disease.