The Iceland international netted either side of the interval as Rangers extended their advantage at the summit to five points.
If Helguson was impressive, it paled in comparison to Adel Taarabt, who was at his irresistible best.
The dynamic midfielder was at his brilliant best as he terrorised Boro's backline, capping his performance with a goal from the penalty spot which wrapped things up.
Clearly buoyed by last week's 3-2 victory at Millwall, Middlesbrough started the brighter of the sides and should have taken the lead in just the first minute.
Australia striker Scott McDonald found space in the area, but, after finding room to work an opening, he saw his effort saved by Paddy Kenny.
QPR, though, were quick to get back into the game with Taarabt and Wayne Routledge causing problems with their direct play.
The former, in particular, was proving particularly difficult to deal with, forcing a smart save from Jason Steele a 20-yard snap-shot.
As the game wore on, Taraabt's influence was becoming increasingly prominent with the the mercurial Moroccan hitting just wide form range before forcing another excellent save from Steele.
He came agonisingly close to breaking the deadlock in the 35th minute when he found himself clean through courtesy of some poor Boro defending, only to hit over.
The home side, meanwhile, were playing plenty of good football but their final ball was leaving a lot to be desired.
The Hoops finally got the reward their endeavour deserved in the 41st minute through Helguson.
Predictably, Taarabt was involved, squaring a lovely ball to the striker, who made no mistake from 12 yards.
Picking up where they left off, Rangers continued to dominate after the interval with the hosts often finding themselves chasing shadows.
And the league leaders soon extended their advantage through Helguson's second.
The impressive Routledge was the architect, jinking his way down the left wing before sending in a delicious centre which Helguson nodded past Steele.
The goal seemed to take the wind out of Middlesbrough's sails as QPR continued to dominate.
They found themselves three-up in the 68th minute when, after being brought down by Merouane Zemmama, Taarabt netted from the spot.
Neil Warnock's side took there foot off the gas thereafter, but, with their defence looking impregnable, they easily saw the game out.
Middlesbrough 0-3 QPR: Match Report - view commentary, squad, and statictics of the game as it happened.