The Latin superstars' scheduled stop at the Honda Center, which was added to their joint tour due to overwhelming ticket demand, will not take place, but one gig at the same venue on Saturday will go ahead - as will two shows next week at the nearby Staples Center in Los Angeles.
The two stars, who are already in California, joined pal Pitbull onstage in Los Angeles on Thursday night.
No reason for the cancellation of Sunday's concert has been given.
The joint tour, which has been playing to sold out crowds across North America, will conclude in Florida next month before Lopez goes solo in Europe and Asia.
She has also just announced plans to tour Australia in December.