Beyoncé Knowles supposedly struggled to hold back tears as she performed on Sunday.

The singer took to the stage at the Pasadena Rose Bowl in Los Angeles for the latest date in her and husband Jay-Z’s On The Run tour.

But it seems the pressure of headlines surrounding the state of her marriage with Jay took their toll on Beyoncé, who was on the verge of tears as she belted out her track Resentment to an arena full of fans.

“She looked like she had been crying from the time the concert began,” an alleged concertgoer told Radar Online.

“Her eyes were really glassy and red, and it looked like she was just going through the motions on stage.”

It was when Beyoncé sang the line “I know she was attractive but I was here first”, about a man’s mistress, that she really struggled to maintain her composure.

According to sources, the star had to pause the performance as she did her utmost to hold back the tears.

“Beyoncé stopped after the word ‘but’ and gestured at her own body in frustration,” the onlooker added. “Not long after, she stopped singing and seemed overcome with emotion. The camera was cut in tight so you could literally see her eyes welling up before she closed them and attempted to collect herself.”

The star’s emotional performance came after claims things are so bad between her and Jay they are staying in separate hotels while on tour.

But concertgoers said it seemed that Beyoncé couldn’t muster up the enthusiasm to pretend everything is fine in her relationship.

“She never really got her energy up again after that and only smiled one or two more times during the rest of the concert,” the source continued. “Any time she interacted with Jay-Z, it seemed like she was just going through the motions. The strain between them was obvious!”