The Kings had dropped the front end of the home-and-home with the Blazers in Portland on Friday 104-91. Sacramento has now lost five straight games since an opening-night win over the Denver Nuggets.
Cousins scored 15 of his 33 points Saturday night in the fourth quarter after Portland had opened a 69-54 lead.
The Kings limited reigning Rookie of the Year Damian Lillard to just four points on 1-of-15 shooting, but gave up 22 points and 14 boards to LaMarcus Aldridge while Wesley Matthews added 21 points. Robin Lopez had a double-double for the Trail Blazers with 12 points and 10 boards.
The rest of the Sacramento starters struggled, with Patrick Patterson, John Salmons, Greivis Vasquez and Marcus Thornton combining for just 16 points on 10-of-23 shooting. The only other Kings in double figures were Ben McLemore, who scored 13 points and made all three of his 3-point attempts in 28 minutes, and Isaiah Thomas, who scored 12 points in 17 minutes.
Portland took advantage of some early foul trouble for the Kings while building a 45-38 halftime lead. Cousins picked up his second foul with 6:27 left in the first quarter and logged just 10 minutes before halftime.
But Salmons, in particular, might as well have had his picture on the side of a milk carton for all the good he did the Kings. In 24 minutes, Salmons missed both of his shot attempts and had three rebounds and one assist. He was a team-worst minus-12 on the night.
The Kings are off until Wednesday night, when the Brooklyn Nets come to town for a 7 p.m. tipoff.