Country-pop songstress Taylor Swift has been pulling out all of the stops on her current 'Red' tour and has brought out some very exciting musical guests, but last night (August 24) was perhaps the most impressive of all.

At her Staples Center performance in Los Angeles yesterday, she welcomed none other than Jennifer Lopez to the stage to treat gig-goers to a joint rendition of 'Jenny From The Block'. Writing on Twitter about the duet, Swift explained that she still hasn't calmed down about it:

"Sang Jenny From the Block with @JLo tonight at Staples Center. STILL FANGIRLING OUT ABOUT IT."

Lopez then shared a snapshot of them posing together (shown below) and accompanied it with the caption: "Thank you for inviting my family to be a part of yours @taylorswift13!!! #RedTourLA." She added: "@taylorswift13 had so much fun with you tonight!!! #RedTourLA #jennyfromtheblock #hairbrushsongs."

Watch the performance here: