The two sets of brothers - frontman Kiaran and drummer Brandon Crook, guitarist Josh and bass player Andy Davidson - were performing on the opening day of the music festival when their chart position was announced on Radio 1.
VIDEO: Watch our exclusive interview with The Sherlocks in the video above.
They celebrated by opening a bottle of champagne at the end of the set and spraying fans before their own Champagne Supernova celebration backstage meeting their own idol and Oasis legend Liam Gallagher.
He sung their praises before he took to the main stage with songs from his forthcoming solo album, As You Were, plus classics, including crowd pleaser Wonderwall. Headliners were chart-topping rock trio Muse. Saturday's headliners are Kasabian and Eminem brings the festival to a close on Sunday.
But the big story of the opening day belonged to The Sherlocks, a fairytale dream come true as they who performed in front of a packed NME/Radio 1 stage.
Afterwards they gave us their first interview as chart stars and thanked the thousands of fans who bought their debut album, Live For The Moment, to make it the biggest moment of their lives.
The Bolton On Dearne lads are the first South Yorkshire band to break into the top 10 with their debut album since the Arctic Monkeys did it 10-years ago.
Kiaran, who described Live For The Moment, as “the soundtrack of seven relentless years of hard graft”, said: "We want to thank all our fans. This means the world to us for our debut album to chart so high. It's been hard work but we have our loyal fans, the Sherlocks Army, to thank for this. It's just the start of our journey."
It was the greatest gift for birthday boy Josh who said: "We had an amazing time on stage at Leeds Festival and now we're going to be celebrating all over again with fans at Reading Festival on Sunday."
BUY THE ALBUM: You can buy the album from all good record stores for visit The Sherlock's official web site to buy special bundles and for download links at www.thesherlocksmusic.co.uk.
VIDEO: Watch The Sherlocks playing Live For The Moment live at Sheffield Arena on our YouTube player - or CLICK HERE.
FACEBOOK LIVE: Watch our Facebook Live stream of The Sherlock's 'secret' gig at Tramlines Crystal Stage - CLICK HERE.
They recorded the album at the world famous Rockfield Studios in Monmouth, South Wales.
It's where Queen turned out Bohemian Rhapsody and icons Oasis, The Stone Roses, Coldplay, Paul Weller, Kasabian, Manic Street Preachers, Stereophonics and more have all recorded.
The Sherlocks were in the expert hands of top producer Gav Monaghan, who has worked with them from the start and recorded The Twang and Editors, producing Nizlopi's chart-topping JCB song in 2005.
He said: "The competition to make this album was fierce because everybody wanted to work with The Sherlocks. I'm glad they picked me because we've smashed it. What makes them successful is their songs, lyrics and hooks."
Live For The Moment Track Listing
1. Will You Be There2. Live For The Moment3. Escapade4. Chasing Shadows5. Blue6. Nobody Knows7. Was It Really Worth It8. Turn The Clock9. Last Night10. Heart Of Gold11. Motions12. Candlelight
For more visit The Sherlocks official web site at www.thesherlocksmusic.co.uk, like them on Facebook at www.facebook.com/TheSherlocksOfficial, follow on Twitter @TheSherlocks and Instagram on www.instagram.com/thesherlocks.