The 'Fire' hitmakers interspersed their set with snatches of other people's songs as they closed the main stage in the southern leg of the event, threading disco classic 'I Feel Love' into 'Stuntman', while the 90s duo Salt N Pepa's 'Push It' was incorporated into their rendition of 'Julie And The Mothman'.
The group received a rapturous response for their hit-laden set, with the crowd defying heavy rain to sing and dance along to 'Processed Beats', 'Shoot The Runner', 'Empire' and 'Club Foot'.
Recent single 'Fire' got the best reception of the night, with frontman Tom Meighan introducing the song by declaring: "This is why you came."
The singer seemed touched by the crowd's response, thanking fans repeatedly and ending the set with: "Chelmsford, I don't know what to say.
"We started this band in 1997 when we were babies, look at us now and it's all thanks to you!"
Other artists to perform at the two-day event - which also has a site in Staffordshire - included The Prodigy, Madness, Paolo Nutini, Stereophonics, Paul Weller, and Kings Of Leon, who headlined the main stage on Saturday (21.08.10).