There was more at stake in Macau than the WBO international welterweight title as 34-year-old Pacquiao, who dedicated the fight to his compatriots back in the Philippines affected by Typhoon Haiyan, looked to prove after successive defeats he was still among the world's best.
Whether he did that against an opponent who did almost nothing to test him was open to debate.
But it was certainly as comprehensive a points win as he could have hoped for, as he did all the hard work in the early rounds and was able to ease off as the final bell approached.
The judges' scorecards read 120-108, 119-109 and 118-110, but such was Pacquiao's dominance that the latter pair were perhaps a little generous to the American.
"It's really important to me to bring this honour to my country, especially the people who are victims of the typhoon," Pacquiao said on Box Nation.
"I hope they're happy because I won the fight."
Rios was on the canvas in the first round but it appeared to be from a slip rather than any devastating work from Pacquiao.
Nevertheless, it was the Filipino who had the better of things in the opening round, and it was the same again in the second as he rained in some powerful combinations which had the American listing just before the bell.
Rios landed a heavy shot to the head of Pacquiao in the third, but in the main he was being outclassed by his opponent, who moved him around the ring at will in the fourth.
With Pacquiao dancing round the ring with ease and a cut opening up above the left eye of Rios, it was tough to make a case for the American having taken a single round by the halfway stage.
The pace slowed a little as the fight moved into its second half, but with Rios effectively in need of a knockout blow, that suited Pacquiao just fine.
Rios finally landed some blows in the ninth, but it was far too little too late to bring him back into the contest.
With Pacquiao now doing little other than staying out of trouble the contest began to lack spectacle until he finished with flurry as the crowd roared him on.
Rios smiled as the final bell sounded, perhaps just happy he had made it to the end, but it was clear who the winner was.
"He's one of the toughest opponents of my career," Pacquiao said. "He took a lot of punches but he's still standing.
"I can fight. I did not consider Rios as an easy opponent. He's tough, he's a very tough boxer. I can still fight faster opponents and good boxers."