Adel Taarabt's first goal of the season set Queens Park Rangers on course for a 2-1 victory over Arsenal at Loftus Road on Saturday to boost the west London club's hopes of avoiding relegation.
Taarabt broke his duck in the 23rd minute with a superb individual effort and while Theo Walcott levelled for the Gunners, Samba Diakite's 66th minute effort secured three points for the home side.
Mark Hughes's team remain in the bottom three on goal difference, but victory against an in-form Arsenal who remain third will strengthen their belief they can survive.
Arsenal came into the game on the back of a run of seven successive league wins but rarely looked likely to extend that run.
Arsene Wenger's side remain in third spot, but defeat means fourth placed Tottenham can close the three point gap between the two rivals if they win their game in hand.
The opening moments suggested this would be another long afternoon for QPR with Arsenal starting the game in the manner expected of a team on such an impressive run of form.
Robin van Persie quickly tested home keeper Paddy Kenny with a low free kick after Walcott had been fouled as Rangers struggled to find a way out of their own half.
The hosts soon showed they had the stomach for the fight, regrouping and taking the game to the in-form visitors.
And it soon became clear Rangers had the capacity to unsettle the visitors with Clint Hill and Bobby Zamora both directing headers close to Wojciech Szczesny's goal.
Hughes' side were winning the midfield battle with Diakite, Barton and Shaun Derry eclipsing the efforts of Arsenal trio Alex Song, Mikel Arteta and Tomas Rosicky.
Arsene Wenger's decision to field Aaron Ramsey in an unfamiliar left-sided role appeared misjudged with the Wales captain largely anonymous in the first half.
When Rangers finally took the lead, it was not simply the result of their greater determination, more a moment of genuine quality from Taarabt.
The Morocco international received the ball with his back to goal and in one movement turned Arsenal defender Thomas Vermaelen outside the visitors' area before advancing and placing a right foot finish beyond Szczesny.
Rangers fully deserved their lead and Arsenal appeared stunned.
Arsenal, though, hit back and were level 15 minutes later as Walcott equalised after being set up by Van Persie.
The England winger is more accustomed to playing the role of provider to his Dutch team-mate but this time he collected a reverse pass and finished at the second attempt after his first effort rebounded back off the upright.
The goal appeared to steady Arsenal who demonstrated far more authority after the break.
They were unable to find a second goal, however, with Kenny twice denying Van Persie with good saves, the second after the Dutch international had broken clear and appeared favourite to score.
Rangers stood firm and when they did manage to press forward, they again exploited the vulnerability of the Gunners defence with Vermaelen again at fault in the build-up to the home side's second.
The centre back slipped at a crucial time, allowing James Mackie to break into the area and pull the ball back for Diakite who finished emphatically from 12 yards.