The O's opened the scoring after four minutes when a Sean Thornton free-kick was headed home by the unmarked Jimmy Smith.
It was 2-0 in the 23rd minute when the hosts were awarded a penalty. Habib Beye was adjudged to have handled in the area under pressure from Adrian Patulea and former Sunderland midfielder Thornton slammed home from the penalty spot.
Newcastle got a penalty of their own on the half-hour when Obafemi Martins was bundled over and Joey Barton stepped up to score.
However, it was the hosts who extended their lead after 53 minutes when Scott McGleish produced a stunning overhead kick to beat substitute goalkeeper Fraser Forster.
McGleish turned provider two minutes later as he cushioned a Jason Demetriou corner into the path of Tamika Mkandawire and he stabbed home.
The Magpies' disastrous afternoon continued with seven minutes remaining as Ryan Jarvis made it five with a neat side-footed finish and it was six three minutes later when Harry Baker coolly slotted home after good work by Loick Pires.