Three points would have taken Rangers to within seven of injury-hit Burnley, who were beaten at home by Sky Bet Championship leaders Leicester earlier in the day.
However, Harry Redknapp's side produced a lacklustre display and Blackpool led through David Goodwillie's 11th-minute opener before Hoilett, on as a substitute, evaded two challenges near the edge of the penalty area and fired home from 25 yards.
Goodwillie, on loan from Blackburn, had taken advantage of some shoddy defending and bundled the ball in at the far post after Andrew Halliday's corner had been flicked on by Chris Basham.
The lively Ravel Morrison often looked QPR's best hope of an equaliser but was well contained by the visitors, not least when he wriggled away from two defenders only for his shot to be blocked by the excellent Gary MacKenzie.
Basham and Goodwillie shot over as Blackpool threatened on the counter-attack in the first half, adding to the palpable anxiety among the home fans.
Those fans' spirits were lifted when key defender Danny Simpson returned to action seven minutes before the break.
Simpson, sidelined for more than two months with a back problem, came on as a substitute for Aaron Hughes, who was struggling at right wing-back and appeared to pick up an early knock.
And Simpson went close to scoring a minute before half-time, when keeper Matt Gilks had to produce a good save to keep out his header from Benoit Assou-Ekotto's left-wing cross.
Redknapp made an attacking change at the interval in an attempt to get his team firing, sending Hoilett on in place of Nedum Onuoha.
Hoilett had an immediate impact, shooting wide after a pacey run towards the penalty area, while Morrison had an effort saved by Gilks as the R's continued to press.
They appealed in vain for a penalty when Morrison went down a challenge from MacKenzie, before a final throw of the dice by Redknapp, who replaced Zamora with on-loan West Ham striker Modibo Maiga midway through the second half.
But it was Hoilett who came up with the equaliser, denying Blackpool a first win at Loftus Road since 1972.
The Tangerines, beaten in 11 of their previous 12 away matches, had to defend resolutely in the final stages and Gilks did well to keep out a stunning strike from Morrison.
But as Rangers pushed forward they left gaps at the back and had a lucky escape when substitute Thomas Barkhuizen got away from Richard Dunne only to slice horribly wide with just keeper Rob Green to beat.