Rovers, needing just a draw to stay in the top flight, bravely fought back from 22-4 down to tie things up at 22-all before Brough’s one-pointer.
There was still time for drama, Terry Campese hitting the post with a long-range drop goal attempt of his own, while Rovers also had a try disallowed by the video referee for a shove.
Huddersfield must have thought they had one foot in Super League for next season when they led 22-4.
They hit the front on six minutes when Ryan Brierley plucked Terry Campese’s pass out of the air and ran 50 metres unopposed for the game’s opening try.
Aaron Murphy’s unconverted four-pointer when established an 18 point lead for the Giants.
Two scores behind with 30 minutes to play, and knowing a point would be enough, the momentum was with the home side.
Matty Marsh’s low kick evaded a number of Huddersfield defenders and Mitch Allgood pounced to reduce arrears to one.
The scores were levelled minutes later when Blair’s towering kick was allowed to bounce by Jermaine McGillvary, and though Mantellato couldn’t get to it, it was touched down behind him by Iain Thornley.
It was a controversial call, that appeared to go with the on-field call, with no real conclusive evidence either way that Mantellato had knocked it on in competition with McGillvary.
Hull KR then wasted three good field position opportunities for a drop goal, and Huddersfield made them pay as Brough showed them how to do it with seven minutes left.
The hosts never really got close enough after that, though Campese gave it a good go from 40 metres, only to see it come back off the post.
As time ticked on, Campese tried a chip and chase on the last from inside his own half, and he managed to get the ball away for Thomas Minns to score.
But on consulting the touch judge and video referee, it was rightly ruled that Campese had pushed Jake Connor in retrieving his kick and the try was chalked off.
That proved to be the end of the drama, and Huddersfield clung on to retain their status in the top flight.
Hull KR will find out their opponents next week depending on the results over the weekend.
If Salford beat Batley, they will qualify for the Million Pound Game. Should Salford lose, a win for London against Featherstone will give them the opportunity to become the second Championship team to earn promotion.