New Young Pony Club incited the first circle pit in the NME/Radio 1 Stage at Reading Festival.
The group mixed tracks from their two albums as the tent began to fill.
Some fans left after a rousing rendition of 'Ice Cream' but the group played 'Lost A Girl' and 'We Want To' back to back to get those remaining bouncing.
"We started the party early," exclaimed singer Tahita Bulmer to massive cheers from the audience.
"They were the best so far," said Lucy, 17 who was in the crowd. "I can't wait to see Biffy [Clyro] though."
The festival continues with sets from Guns n' Roses, Queens Of The Stone Age and more.