Benayoun had a night to remember as Rangers ended fellow promotion hopefuls Wigan's 10-match unbeaten streak, netting the decisive goal before seeing red in stoppage-time.
QPR manager Harry Redknapp declared in his programme notes that he still thinks his side will be promoted, despite the fact they will almost certainly have to navigate their way through the play-offs to do so.
They cemented their place in the top-six as the season enters the closing stages with a 1-0 win against Latics, who left Loftus Road empty handed due to wayward finishing and Robert Green's fine performance.
Clint Hill was the unlikely source of the game-changing moment, providing a wonderful flick through for Benayoun to slot home with 16 minutes on the clock.
QPR spent much of the rest of the game on the back foot, with James McClean proving a threat throughout and Ivan Ramis rattling the crossbar.
The hosts were somewhat fortunate to keep a 17th clean sheet of the season, truth be told, although they came close to a second when Ravel Morrison hit a free-kick against the underside bar before Benayoun was sent off in stoppage time.
Uwe Rosler's side were made to pay for their poor start to the match, which began with Bobby Zamora being bundled over in the penalty area - with only the offside flag coming to their rescue.
It epitomised the visitors' struggle to get a foothold on proceedings, yet they produced the first clear-cut chance when Josh McEachran, on loan from Chelsea, fizzed a 20-yard free-kick just wide.
It was a rare moment of respite for Wigan as QPR continued to press, leading to the opener after 16 minutes.
After neat play down the left channel, a delicate flick from hulking centre-back Hill put through Benayoun to poke past Ali Al-Habsi in the Wigan goal.
It was a fine team effort and one which appeared to wake Rosler's side from their slumber.
James Perch and Nick Powell tested Green with fierce drives, as Latics lay siege on the QPR goal.
The former England international did well to push a McClean drive around the post soon after, before again denying the Irishman from the resulting corner.
Morrison and Niko Kranjcar saw tame efforts denied as QPR appeared to settle, only for McClean to drag a low strike inches wide as half-time approached.
The hosts were struggling to cope with the Wigan onslaught, with James McArthur somehow bundling wide moments after the restart.
McClean had an effort saved as Latics upped the ante, with Ivan Ramis rattling the crossbar in front of the 271 visiting fans.
Benayoun had an effort deflected wide as the R's attempted to move play into the Wigan half, before an outstanding Morrison free-kick hit the underside of the bar and Zamora's rebound was cleared off the line.
It began a frantic final 10 minutes in which Benayoun was sent off for a second bookable offence, before Green produced a wonderful save at full-strength to deny substitute Nicky Maynard.