QPR had captain Nedum Onuoha sent off on their way to a sixth consecutive defeat – their worst run of results for 21 years.
They got off to the worst possible start by falling behind on 11 minutes.
Brighton forward Sam Baldock collected a pass from Dale Stephens and drifted away from Onuoha before firing a shot into the top corner from just outside the box.
Rangers did have a bright spell in the wake of conceding and tested Albion keeper David Stockdale on a couple of occasions.
The former Fulham man first denied Massimo Luongo and later kept out a shot from Idrissa Sylla at his near post after good work by Pawel Wszolek.
Sylla squandered a clearer chance, having pulled down Jake Bidwell’s cross only to poke wide.
Any hopes they had of getting back into the game against the Championship pace-setters, who had only been beaten twice at home in the league in 2016, vanished during a five-minute period early in the second half.
Luongo’s reckless challenge on Baldock gave Brighton a penalty, converted by Glenn Murray for his 15th league goal of the season.
And when Onuoha was harshly dismissed – Baldock going to ground on the edge of the box after what appeared little more than an honest tussle – Rangers’ task was further complicated.
Anthony Knockaert added a third, finishing off a neat move by cutting inside in the right channel and slotting past Alex Smithies.
Stockdale tipped over Sylla’s header as QPR’s wait for a goal continued – their drought now stretches to 360 minutes – and this current run of form is their worst since the 1995-96 Premier League season, when they were relegated.
QPR: Smithies, Perch, Onuoha, Hall, Bidwell, Wszolek, Cousins (Sandro 80), Borysiuk (Mackie 59), Luongo, Ngbakoto (Kakay 80), Sylla.
Subs not used: Ingram, Washington, El Khayati, Shodipo.
This post was last modified on 27/12/2016