With the set list now apparently disregarded, drummer Gary Powell gave up his seat to Doherty for an impromptu rendition of The White Stripes' Seven Nation Army, before the crowd were urged to join in the Foundations' Build Me Up Buttercup.
Medical officers and security staff rushed to help people crushed at the front, and photographer Leon Neal tweeted: "Chaos at the Libertines gig in Hyde Park. Many crushed with medics dragging people from the crowd."
Things eventually settled down and the gig resumed as planned, and in between songs a greying Doherty used his few interactions with the audience to pay tribute to football club Queens Park Rangers, Smiths guitarist Johnny Marr and Gerry Conlon - who was among four people wrongly imprisoned for the 1974 IRA Guildford pub bombings, and who died last month.
The hit-filled set was the band's first in more than four years in the capital, coming as the latest gig in Barclaycard's British Summer Time series.
Barat and Doherty - famously once romantically linked with supermodel Kate Moss - put their often-talked-about personal differences aside as they frequently shared a microphone and embraced mid-set while the sun went down on Hyde Park.
The set included crowd favourites such as Can't Stand Me Now, Don't Look Back Into The Sun and What A Waster before more interruptions - mid-song - as Barat was instructed to request that bare-chested fans stop scaling the delay tower.
An aptly quirky sing-along of the Hokey Cokey closed the show.
The band also used the gig to announce two further London concerts, at the Alexandra Palace, on 27 and 28 September.
Doherty later confirmed the dates on Twitter and said ticket would go on sale on Monday, adding: "Enjoy."
- Independent