Taylor Swift wowed the O2 Arena audience after making a surprise guest appearance during Haim's Thursday night London show.
Fans screamed as the 32-year old joined the three-sister girl band on stage on the final UK stopping point of their ongoing One More Haim tour.
The group were clearly delighted too as Este, 35, Danielle, 32, and Alana, 29 all applauded and bowed to the superstar as she strutted towards the centre of the stage.
Introducing Taylor, Danielle declared: "Not only is this person that I’m about to bring out the most incredible singer, songwriter, producer, and an amazing person all round.
"She’s one of our close friends, so the O2 arena - will you please welcome to the stage Taylor Swift."
Shake It Off star Taylor quickly responded: "I heard that my girls were playing in London at the O2 and I thought, 'I'm gonna have to see that.' And it looks like there's about 20,000 other people that also thought that, too.”
"We had a thought, that if we were to do some sort of mashup, we could possibly maybe get you to sing the loudest that you have sung all night."
A medley of Haim's 'Gasoline' and Taylor's 'Love Story' then ensued as the crowd's roar reached another level.
Footage of the collaboration soon circulated on social media causing a stir amongst 'Swifties', with one Twitter user commenting: "Tears in my eyes, I missed her terribly. I can't believe this is real."
Another wrote: "OMG I would not know how to act. She looks and sounds SO GOOD!"
A third added: "THIS IS SO FREAKING COOOOOOL! She looks hot and the mashup of Love Story and Gasoline, omg actual chills! To come out of hiding and perform, she must be ready for the next stage. Our August theories feeling bang on the money right now. Blondie is coming back."
A fourth said: "She hasn't been on stage in so long. She's truly slaying. I love her Taylor go on tour please and thank you."
Haim have released three albums since their 2013 inception, with their biggest hit 'The Wire' reaching number 16 in the UK singles chart.
Taylor, meanwhile, last toured in 2018 whilst promoting her 'Reputation' album.
Fans have been desperate for more ever since, but the coronavirus pandemic put paid to her 2020 plans.
Thursday night's appearance, however, will have raised fans' hopes significantly that her own dates are in the pipeline.
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