Second-half strikes from Nahki Wells and Matt Smith proved the difference as QPR made it through to the fifth round of the FA Cup for the first time in 22 years with a 2-0 win at the expense of Portsmouth at Loftus Road.
In a quiet first period, Darnell Furlong's header against the bar from Luke Freeman's centre was the pick of the chances.
Extra-time looked a distinct possibility heading into the break, but the hosts' top-scorer Wells broke the deadlock with 20 minutes left, capitalising on chaos at a corner to bundle in from a yard out.
The result was then made safe seven minutes later as the talismanic Freeman delivered a sumptuous free-kick which Smith gleefully powered home to set up a home tie against Watford on February 15.
Fourth-round replays don't usually whet the appetite, but 13,115 was a creditable turnout, with the 2,941 travelling contingent making most of the noise.
QPR did enjoy the lion's share of possession in the opening period, with the Championship side coming closest when Furlong's flicked effort left Craig MacGillivray rooted to the spot, with the woodwork coming to his aid.
Portsmouth had progressed to this stage with three clean sheets and three away wins to their name, and despite not possessing the same attacking potency as their hosts, the central defensive partnership of Christian Burgess and Matthew Clarke was proving difficult to breach.
The game burst into life around the 55-minute mark.
Wells latched onto a through-ball from Massimo Luongo, skipped past Burgess and bore down on MacGillivray in the visiting goal before a sensational sliding block from Clarke prevented the favourites from breaking the deadlock.
The contest was becoming far more open and shortly after his initial attempt, Wells blasted an effort just wide, with Freeman doing the same moments later.
However, the game was still awaiting its first shot on target going into the final 25 minutes, with plenty of midfield endeavour leading to precious little goalmouth action.
Kenny Jackett's decision to bring on attacking midfielder Gareth Evans after an hour then almost paid dividends, but the former Fleetwood man skewed his effort wide.
That was to prove costly just a few minutes later when Freeman's centre was met by a bullet header from Smith. After pinball in the penalty box, the ball eventually squirmed invitingly into the path of Wells, who bundled in on the goalline.
Freeman was in the thick of the action again shortly afterwards, with the former Bristol City winger punishing Burgess' decision to scythe down Luongo, with a wicked delivery thumping against the temple of Smith and flying into the top corner.
Portsmouth continued to press, but their lack of accuracy proved their undoing and the Hampshire side now turn their attentions to League One and EFL Trophy matters.
