The Clarets' play-off prospects suffered a further blow as defeat at Bristol City extended their winless run to three games.
Goals either side of half time from on-song Robins' frontmen Brett Pitman and Nicky Maynard sent Burnley into the international break still three points adrift of a top-six place.
Having lost their hard-earned momentum at just the wrong time, Eddie Howe's men slipped to eighth in the Championship table as they tasted defeat away from Turf Moor for the first time in five games after rarely threatening to re-launch their promotion push.
Lacking the cutting edge to make the most of their brief periods in control and fight back from Pitman's opening strike, the Clarets were then undone by another defensive lapse as Maynard clinched impressive City's fifth win in five games.
Fortunately for the Clarets, results elsewhere again limited the damage as wins proved elusive for the their stuttering play-off rivals.
But Burnley know they must make the most of the timely chance to re-group during the international shut-down to set themselves up for the big finish they now need to keep alive their hopes of a top-flight return.
The Clarets' bid to bounce back from the disappointment of dropping five points in successive home games meant changes to Howe's line-up as the Burnley boss looked to bolster his back line with the re-call of Andre Bikey at Ashton Gate for his first start since December.
Eddie Howe ponders defeat at Ashton Gate
Marvin Bartley was handed his full Burnley debut in place of the injured Dean Marney and Wade Elliott also returned to starting duty in midfield in an effort to get the Clarets firing.
But it was in a defensive position that Elliott made his first contribution against the revitalised Robins as his goalline clearance from Maynard kept City out after just three minutes.
Bristol's bright start also brought an early booking for Danny Fox for a foul on dangerman Albert Adomah, which will keep the full-back out for two games when the Clarets' resume their campaign against Ipswich Town in a fortnight's time.
And on the other flank, Jamal Campbell-Ryce launched a dangerous run into the penalty area which forced Lee Grant into a smothering save before the Clarets eased their way into contention.
Ross Wallace forced former England international David James to go full length to turn his low shot round the post eight minutes before the half time as Burnley broke with real purpose.
And three minutes later James had to make an even better save to deny Bartley an equaliser and the chance to cap an encouraging start with his first Burnley goal.
Jay Rodriguez's clever pass released Bartley but rather than shoot first time he opted to try and take the ball round James and the veteran stopper was able to spread himself and save at the midfielder's feet.
Marvin Bartley is denied by David James
And rather than lead at the break, the Clarets found themselves going in behind as the Robins then grabbed the lead through Pitman.
The striker scored plenty of goals under Howe when they worked together at Bournemouth and City's top scorer showed his predatory instincts are still intact when he pounced after the Clarets had failed to deal with an Adomah cross to control the ball and thump a half-volley past Grant.
Tyrone Mears claimed he should have had a penalty when he went tumbling in the box as Burnley looked to hit straight back.
And having survived a bad miss from Maynard four minutes into the second half, as well as a defensive mix-up that almost let in Adomah, the Clarets looked capable of levelling as they enjoyed their best spell of the game.
Bikey twice went close with headers as Burnley pushed the home side onto the back foot.
But despite several promising positions the Clarets couldn't force the decisive opening and with 20 minutes to go they effectively waved goodbye to the points.
Chris Eagles sums up the Clarets' frustration
A long ball out from the back launched Maynard on the chase and when Clarke Carlisle left his attempted back-pass short, Maynard nipped in to deliver the killer blow.
City then went chasing a third with Adomah forcing Grant into a fine save before seeing his effort from the resulting corner blocked in front of goal.
A half-chance for Rodriguez at the other end might have set up a late fightback had the Clarets' top scorer been able to control a Chris Eagles' pass in the penalty area with ten minutes to go.
And the persevering striker forced James into a near-post save just before the end as the visitors staged a late vain bid to ruffle the Robins' feathers.
But coming up short in both penalty areas ultimately proved costly as the Clarets remained disappointingly off the pay-off pace with games starting to run out.
Burnley: Grant, Mears, Fox, Carlisle, Bikey, Bartley, Cork (Delfouneso 62), Elliott (Alexander 90), Eagles, Rodriguez, Wallace (Iwelumo 68). Subs: Duff, Edgar, Easton, Jensen.
Booked: Fox 6, Mears 58, Rodriguez 78, Carlisle 87
Bristol City: James, Spence, Stewart, Caulker, Nyatanga, Adomah, Cisse (Johnson 38), Elliott, Campbell-Ryce, Pitman (Keogh 90), Maynard (Clarkson 90). Subs: Woolford, Ribeiro, Edwards, Gerken.
Booked: Campbell-Ryce 67, Stewart 75
Referee: Mark Brown