LATICS crashed to another damaging defeat to a relegation rival as a painfully average QPR side inflicted some real capital punishment.
Aside from a bright opening 10 minutes, when Latics could and perhaps should have taken the lead and the initiative, the visitors were second best across the park and got exactly what they deserved.
Trailing 2-0 at the break thanks to a Heidar Helguson penalty - awarded for an inexplicable handball from James McCarthy - and a blinding free-kick from Akos Buzsaky, Latics briefy threatened a comeback when Hugo Rodallega steered home a glorious free-kick with a quarter of the game still to go.
But hopes of an unlikely point were quickly extinguished when Tommy Smith lashed home a belter from 30 yards.
And without more heroics from Ali Al Habsi - who made a string of fine saves including a second penalty from Helguson - the scoreline coould have been even more emphatic.
With 16 games to go, Latics are now four points from safety, with the worst goal difference in the top flight, and a nice trip to Tottenham to look forward to tomorrow week.
Roberto Martinez had made three changes for the trip, bringing in Ben Watson, Steve Gohouri and Emmerson Boyce for a first start in over two months, with Ronnie Stam and Albert Crusat dropping to the bench and Antolin Alcaraz ruled out by injury.
The big team news as far as Rangers were concerned was the return of Joey Barton after suspension for Mark Hughes’ first home Premier League match in charge, with Federico Macheda - reportedly a recent Latics loan target - on the bench.
Despite all the pre-match talk being centred on Rangers, it was Latics off to a flyer - and the visitors should have been ahead within three minutes.
Victor Moses was fouled down the left, and Jordi Gomez swung in a delightful free-kick with his left foot that found Gohouri unmarked 10 yards from goal.
The Ivorian elected to volley towards goal when he probably had time to control it such was the space around him, but the ball veered agonisingly wide of the far post with Paddy Kenny beaten.
Moses was causing more problems for Luke Young in Wigan’s next attack, skinning the right-back on the outside and getting to the byline, and his cross was only inches in front of the onrushing Rodallega.
Al Habsi was called into the action for the first time on 13 minutes when Young sliced a cross so badly it almost looped into the far corner of the net, the goalkeeper backtracking and tipping it over the bar for a corner.
Poor play by Gohouri presented Rangers with a shooting chance on the edge of the area, although DJ Campbell pulled his effort well wide of the target.
Buzsaky did better with Rangers’ next opportunity, although his snap-shot still cleared the bar as Al Habsi watched it go over.
It was clearly a sighter for Buzsaky, who then fired in a super swerving effort from distance that Al Habsi only just managed to help round the post.
The respite was only temporary, however, as Barton’s corner was handled as it zipped towards the penalty spot by McCarthy, referee Jon Moss having no option but to point to the spot and caution the midfielder.
Al Habsi had already saved three spot-kicks so far this term, and he nearly made it four - guessing correctly and almost getting his left hand to Helguson’s assured spot kick.
The goal was a real blow to Latics, who had started so positively but had found themselves increasingly on the back foot as the half progressed.
Al Habsi was called on to turn a free-kick from Young round the post as Rangers pushed for a second, before Latics mounted a rare attack of their own as half-time approached.
Rodallega looked like he was in behind the Rangers backline after a long ball from Boyce, but the Colombian clearly used his hand to control the ball which was spotted by the linesman.
It was just as well for Anton Ferdinand that the referee’s whistle had gone, as the centre-back then brought Rodallega down as he shaped to shoot which would surely have brought about a penalty and a red card.
And Rangers made the most of their let-off by doubling their advantage just before the break.
Gohouri was once again the culprit, conceding a needless free-kick 25 yards from goal as Campbell found himself outnumbered deep in Wigan territory before drawing the foul.
And Buzsaky made him pay the harshest penalty by curling a superb free-kick past Al Habsi and into the net via the far post.
In fairness, the second goal was no more than Rangers warranted for their dominance, and no more than Latics deserved for the way they had allowed their opponents to take control without too much of a fight.
Martinez tried to shake things up at the interval, sending on Conor Sammon for McArthur - who was a long way from being the worst Latics player, but who paid the penalty for a more attacking approach.
And the Dubliner was quickly into the game, putting himself about in typical fashion and not allowing the Rangers backline any time on the ball.
It was almost game over shortly after the restart when Buzsaky allowed the ball to bounce 25 yards from goal before hitting a dipping volley that was arrowing towards the top corner, before Al Habsi’s left hand intervened at the expense of a corner.
A couple of half-chances then fell to Gomez as Wigan tried to get themselves back into the game, but the first attempt was woefully off target and the second barely made it through to goalkeeper Paddy Kenny.
That was it for the Spaniard, compatriot Albert Crusat replacing him on the hour mark as Martinez opted for more pace.
And Latics gave themselves a real shot in the arm with 25 minutes left via a huge lifeline from Rodallega.
Maynor Figueroa was fouled by Barton in centre-field as he tried unsuccessfully to play in Watson down the Wigan right.
And Wigan’s all-time Premier League goalscorer curled a majestic set-piece over the wall and inside the left-hand post to the delight of the away end behind Kenny’s goal.
It was only Rodallega’s second goal of a frustrating campaign, and he made a point of repeatedly pointed to the badge on his shirt in the direction of the away end to seemingly underline his commitment to the cause.
Martinez went for broke by immediately making his third change, sending on Stam for Boyce to add more of an attacking threat down the right-hand side.
But Latics nearly shot themselves in the foot by conceding a second penalty of the game within seconds.
A collision on the edge of the Wigan box between Gary Caldwell and Helguson seemed innocuous enough, but the official clearly thought the defender was responsible for the pair ending up on the deck and pointed straight to the spot - much to the Scot’s amazement.
Again Helguson placed the ball on the spot, but this time Al Habsi outwitted him by guessing that he’d go for the other side and pulling off a fine save with his right hand.
Latics sensed that this could yet be their day, and Sammon soon found himself clean through down the right channel with Rodallega and Moses busting a gut to get into the box to support him.
Unfortunately, the striker chose to shoot at goal from a difficult angle, and pulled it well wide of the far post.
Helguson almost made amends for his penalty miss with a blinding goal to kill off Wigan, only for his left-foot volley to fly inches beyond the far post.
But the home side did find their third goal with 10 minutes remaining when substitute Smith was given far too much time and space 30 yards from goal, and he responded by smashing an unstoppable right-foot shot past Al Habsi into the top corner.
Latics: Al Habsi 9; Boyce 6, Caldwell 5, Gohouri 5, Figueroa 6; McCarthy 5, Watson 5, McArthur 6; Gomez 5, Moses 7; Rodallega 7.
Subs: Pollitt, Lopez, Stam (for Boyce, 69) 6, Crusat (for Gomez, 61) 6, McManaman, Di Santo, Sammon (for McArthur, 46) 6.
QPR: Kenny; Young, Hall, Ferdinand, Hill; Mackie, Barton, Buzsaky, Wright-Phillips; Campbell, Helguson.
Subs: Cerny, Orr, Derry (for Buzsaky, 83), Ramage, Smith (for Campbell, 46), Macheda, Bothroyd.
Star Man: Ali Al Habsi: Kept Latics in it with a string of super stops, badly let down by those in front of him.