Ed Sheeran told his fans that he had made mistakes after Macklemore was dropped for making pro-Palestinian remarks on stage this month.
Earlier, pro-Palestinian protesters had gathered near the stadium to express solidarity with Macklemore.
The British singer's backing band and opening acts boycotted the event – leaving Sheeran alone on stage to address the crowd.
"I have tried in my career not to be a political commentator of any kind, because I want my music and shows to be about unity, not division," Sheeran said. "But this is a humanitarian issue, and I cannot hide how I feel about it anymore."
The BBC's Carl Nasman was at the concert.