Norwich's late winner against Derby means Rangers need another point to rubber-stamp their promotion back to the top flight for the first time in 15 years.
But Cardiff would also have to engineer a 13-goal swing to deny Neil Warnock the seventh promotion of his managerial career.
Warnock's long-time leaders have stuttered on the home straight and David Amoo's equaliser made it a defeat and three draws from their last five outings.
But the fans still sprinted on to the pitch as a packed Loftus Road partied in the spring sunshine while even Flavio Briatore, no longer the Rangers chairman but still a shareholder, put in a rare appearance to join the knees-up.
When Briatore bought the club in September 2007 he boldly claimed they would be in the Premier League within four years - and despite a fair few hitches along the way the Italian has just about delivered that promise.
Warnock is Rangers' ninth manager since the ex-Formula 1 chief bought the club, and his side have virtually led the race from pole to flag.
QPR never do things the easy way, though, and as well as the maths there is still the small matter of a Football Association hearing into the transfer of midfielder Alejandro Faurlin in less than a fortnight to negotiate.
The club are confident they will not be deducted points, however, and certainly no-one in this part of west London seemed unduly concerned when the final whistle blew this afternoon.
Hull arrived as potential party poopers with an impressive unbeaten record in their last 16 away matches.
They almost put a dampener on proceedings in the opening minute when Matty Fryatt got clear in the penalty area, but Paddy Kenny made a fine save with his legs.
And Rangers made the breakthrough soon after with Adel Taarabt unsurprisingly the architect.
The Moroccan threw one of his occasional tantrums and asked to be substituted when these sides met earlier this season.
But he silenced the taunts of the away fans with a superb through-ball to the turbo-charged Wayne Routledge, who roared past the Hull defence before slotting his fifth goal of the campaign past Matt Duke.
The rest of the first half was all Rangers with Heidar Helguson heading over and also forcing a fine save from Duke, and Clint Hill seeing an effort scrambled off the goal-line.
Hull threatened shortly after the interval with Fryatt's glancing header from James Chester's cross drifting wide and a last-gasp Fitz Hall tackle also denying the City striker.
At the other end Taarabt could have settled it when he burst forward but he uncharacteristically screwed his shot wide.
Instead the hosts were stunned with nine minutes remaining when substitute Amoo latched on to Hope Akpan's ball over the top, steadied himself and crashed a superb 20-yarder past Kenny to deny the keeper a 25th clean sheet of the season.
Still Rangers poured forward and Patrick Agyemang lobbed over before Faurlin, of all people, came agonisingly close to a winner when his free-kick was tipped past the post by Duke.
But Rangers, who suffered relegation to League One and administration since they dropped out of the Premier League, are now planning to rub shoulders with neighbours Chelsea and Fulham once again next term.