Southend continued their remarkable Coca-Cola Championship revival as QPR crashed to an eighth straight away defeat at Roots Hall.
A freak goal from Lee Bradbury, a tremendous second from Mark Gower, a towering header from Efe Sodje and two late long-range efforts from Kevin Maher earned the Shrimpers a richly-deserved win that edges them to within a point of climbing out of the bottom three.
The hosts also had plenty of chances to have added to that scoreline, although the visitors were robbed of a penalty when Lee Cook was tripped in the box when it was only 1-0.
Southend boss Steve Tilson made two changes from the side that drew 1-1 at Stoke last time out, Alan McCormack and Adam Barrett the men recalled.
Opposite number John Gregory lined up with the same starting XI from the 3-1 victory over Burnley, which ended the club's four-match losing run in all competitions.
Southend were first to threaten, top scorer Freddy Eastwood's angled drive whistling over the top of the crossbar inside six minutes.
They then should have taken the lead less than two minutes later when the unmarked Peter Clarke headed over Maher's corner.
However, seconds later they were handed their comic opener, courtesy of Simon Royce.
The Rangers keeper drilled a clearance straight at Bradbury, and the ball rebounded off the striker's right foot and trickled into the net.
More poor goalkeeping almost led to a second in the 17th minute, Royce failing to claim Jamal Campbell-Ryce's right-wing cross.
The ball broke to Gower, whose shot was cleared off the line by Sampsa Timoska.
The last thing Rangers needed was more controversy following this week's mass brawl with the Chinese Olympic team this week but tempers almost boiled over midway through the half when Gareth Ainsworth took exception to a bit of retaliation from McCormack.
Royce then redeemed his earlier error when he prevented an own goal by tipping Steve Lomas' glanced header round the post following a Maher free-kick.
Playing with the confidence that has come from recent results, Southend put together a superb passing move on the half hour to set up Bradbury for a shot which was too close to Royce.
QPR, meanwhile, were offering virtually nothing as an attacking force although they were denied a clear penalty when Clarke tripped Cook.
Neither side made changes at the interval but, once again, Southend looked the more threatening.
Danny Cullip narrowly avoided turning Eastwood's fierce cross into his own net five minutes into the half.
QPR had their first genuine attempts on goal just past the hour mark when Adam Bolder and Cook both shot too close to Darryl Flahavan.
All Rangers' hard work was undone when they fell asleep at the back defending a straight Maher free-kick.
Gower was allowed to escape his marker but still showed tremendous skill to bring the ball under instant control and finish inside Royce's near post.
Flahavan prevented Rangers getting back into the game when he got fingertips to Martin Rowlands' curling effort, which had taken a nick off Clarke.
Gregory threw on Ray Jones for Cullip, while Tilson responded by replacing Gower with Richie Foran.
Neither substitute had time to make an impact before Sodje rose highest to nod in Maher's corner from close range.
McCormack had a last-minute header disallowed for offside before Maher got the goals his performance deserved when he fired home from 20 yards.
He then curled in a 25-yard free-kick as the hosts romped to a fourth win from their last six league games.
Teams
Southend: Flahavan, Hunt, Clarke, Sodje (Francis 87), Barrett, Campbell-Ryce, McCormack, Maher, Gower (Foran 77), Eastwood (Harrold 87), Bradbury.
Subs Not Used: Collis, Hooper.
Goals: Bradbury 9, Gower 70, Sodje 79, Maher 90, 90.
QPR: Royce, Mancienne, Cullip (Ray Jones 77), Stewart, Ainsworth, Lomas, Bolder, Timoska (Rehman 68), Rowlands, Blackstock, Cook.
Subs Not Used: Cole, Nygaard, Smith.
Booked: Ainsworth, Rowlands, Bolder, Blackstock.
Att: 10,217
Ref: P Walton (Northamptonshire).