The visitors seemed on course for an unlikely point when Charlie Austin cancelled out Nikica Jelavic’s opener after Joey Barton saw red but N’Doye made Hull’s extra man count with a close-range header in the 89th minute.
The result moves Hull up to 15th in the table, while Rangers are only above the relegation zone on goal difference with games against Arsenal, Tottenham and Crystal Palace on the horizon.
It seemd a must-win game for both sides with both above the relegation zone but Rangers had been buoyed by the permanent appointment of Chris Ramsey, who had secured their first away points of the season with a 2-1 win at Burnley.
Hull made the early running, though, and much of their good work came through Ahmed Elmohamady down the right with strikers N’Doye and Jelavic the target.
It was a QPR mistake in the 16th minute that led to them conceding the first goal. As the ball floated into the box Steven Caulker headed weakly back across goal and Jelavic made him pay with a clinical volley.
QPR went close to an instant reply, Barton crossing for debutant Darnell Furlong, whose looping header had Allan McGregor scrambling at the far post.
The came the sending-off and while Furlong set events in motion, leaving his foot in on Jelavic, Barton – who later apologised for his actions – can have no complaints about the ninth red card of his career.
After a shove on Alex Bruce, he appeared to get involved in a war of words with Huddlestone before lashing out again.
His dismissal almost cost QPR immediately as Jelavic nodded a fraction wide but Austin got the Londoners back into the game six minutes from half-time when Matty Phillips sent a diagonal cross into the box from the right wing.
The striker was there to head it home and marked his equaliser by hobbling away and clutching his knee – a
none-too-subtle jibe referencing the failed medical that cost him a move to the KC Stadium in 2013.
Hull went for the win, determined to make their extra count, and QPR were indebted to several impressive saves from Rob Green.
Bruce threw on Sone Aluko and Pablo Hernandez in search of the winner deadline-day signing N’Doye finally struck, heading in a Robbie Brady ball after Green had denied him moments earlier.
It was the Senegalese striker’s second goal in as many games – but this one the perfect way to mark his 30th birthday.
Hull: McGregor (6), Dawson (7), Bruce (6), McShane (6), Elmohamady (7), Livermore (6), Huddlestone (6), Meyler (7), Brady (7), Jelavic (8), N’Doye (8).
Used subs: Hernandez (5), Aluko (5), Ramirez (5).
QPR:Green (8), Yun (7), Caulker (6), Ferdinand (6), Furlong (7), Phillips (8), Henry (6), Barton (2), Kranjcar (5), Zamora (6), Austin (7).
Used subs: Traore (5), Zarate (5), Doughty (6)
Man of the match: Robert Green