Watford progressed to the quarter-finals of the FA Cup with a hard-earned 1-0 victory over QPR, despite being some way short of their best at Loftus Road.

Etienne Capoue's gift of a goal put Watford to within one victory of reaching the final four at Wembley - after their Championship hosts had wasted several chances.

Against a near full-strength team that had lost their past five league fixtures, Watford manager Javi Gracia made five changes to his starting XI from the weekend win over Everton, resting Ben Foster, Craig Cathcart, Abdoulaye Doucoure, Gerard Deulofeu and Adrian Mariappa.

An often stretched affair was consistently played at a high tempo and with intensity, but there were few threats on goal before the 28th minute when, after Ken Sema was dispossessed, Daryl Janmaat seized on the loose ball just inside the area and stabbed narrowly over.

When Heurelho Gomes, given a rare start in goal over Foster, then demonstrated a lack of match practice by conceding a corner with a misplaced kick, QPR were almost instantly presented with a fine chance to take the lead and were thereafter largely impressive.

The goalkeeper unconvincingly punched the resulting corner to Massimo Luongo, who from the edge of the area controlled possession before connecting well, but shooting narrowly wide of the left post.

Matt Smith then should have found the back of the net when well-placed, but sent a header wide, although he was offside, and, with QPR applying further pressure, Gomes was forced into a fine save.

Leading a counter-attack from inside his own half, the influential Luke Freeman carried the ball deep into Watford's before floating a pass to Nahki Wells, who stretched to shoot towards the bottom right corner where the diving Gomes stretched to tip wide.

It was in the first minute of first-half stoppage time that, against the run of play, the visitors fortuitously took the lead.

Jose Holebas' left-wing corner found Tom Cleverley at close range and the midfielder's complete mis-hit landed in the path of Capoue, who watched as the ball bounced and crept beyond Joe Lumley's reach and in.

Gracia chose not to make any half-time changes and was almost punished in the 62nd minute when QPR again went close.

Under minimal pressure Christian Kabasele needlessly gifted possession to Wells with a misplaced pass and the striker nearly capitalised by curling narrowly wide.

The hosts continued to dominate and created their clearest chance in the 88th minute, but their failure to score summed up their evening.

Darnell Furlong met a deep cross at the back post and sent it back across the face of goal to Toni Leistner who was free on the left. The defender slid in on a near-open goal, but somehow missed from a yard out.