Before defeat against Watford the Clarets had only conceded three or more goals in a single game six times in 76 competitive appearances.
Burnley have been famously impermeable under Sean Dyche's reign, conceding 39 goals in 38 Premier League games last season, and a clean sheet against Southampton at St Mary's on the opening weekend suggested they'd be hard to breach once more.
However, starting with the Hornets, they've now leaked three or more goals in three successive outings as Fulham eclipsed the goalscoring exploits of Olympiakos, who saw off the Clarets in the Europa League play-off midweek.
It's frighteningly uncharacteristic for a side who had barely allowed their opponents three shots on target in recent times, nevermind three goals.
And, whether it's down to fatigue from Europa League involvement, or simply an abnormal phase, Burnley are conceding goals in the embryonic stages of halves and, on occasions, two in alarmingly quick succession.
Watford netted as early as the third minute at Turf Moor, and again in the 48th and 51st minutes, while Olympiakos restored their lead at the Karaiskakis Stadium just three minutes in to the second half.
Those bad habits stretched in to the game at Craven Cottage when Jean Michael Seri opened the scoring in the fourth minute while striker Aleksandar Mitrovic netted a quickfire double before the interval.
It was far from the ideal start when Ivorian Seri, signed from Nice for £25m in the summer, opened his account for last term's Championship play-off winners.
The 27-year-old's touch from Luciano Vietto's first assist of the fixture took his away from Jeff Hendrick on the edge of the penalty and his finish was a peach, driving the ball in to the top corner.
However, the Clarets are also renowned for their character, endeavour and 'never say die' attitude under Dyche and, surely enough, they restored parity just seven minutes later.
Hendrick's initial attempt from Aaron Lennon's breakaway and cross was blocked by Denis Odoi but the Republic of Ireland international jumped on the pieces to fire the ball in to the roof of the net.
Andre Schurrle, who owns a World Cup winners medal, was another new addition for the Cottagers, joining on loan from Borussia Dortmund, posed a constant threat when cutting infield from both flanks and it took a strong hand from Joe Hart to keep his right-footing strike from creeping in at the near post.
Hart would deny Fosu-Mensah moments later, this time with a more routine stop, but the England international was caught out when the home side restored their lead in the 36th minute.
Tom Cairney's looping cross caused major issues as it span away and dropped beyond Hart and James Tarkowski and Mitrovic, stood on the far post, simply helped the ball over the line with his head.
That single goal deficit quickly became two when Mitrovic, who scored for Serbia during the World Cup in Russia, time his run to perfection, getting beyond Ben Mee and ahead of Stephen Ward to meet Vietto's cross, before powering a header past Hart.
Again, the visitors displayed that grit and determination to dig in and get themselves back in to the game.
The club's central defensive duo combined from substitute Charlie Taylor's corner as Mee headed in to Tarkowski and the latter, level with Maxime Fosu-Mensah, turned the ball home to make it 3-2 before half-time.
After Schurrle threatened again, bending an effort on to the crossbar when once again cutting inside from the angle of the area, the game opened up even more as Dyche looked to salvage a point, introducing both Sam Vokes and Ashley Barnes.
But the more Burnley pressed, the more Fulham found holes to break in to. It was a case of close, but no cigar, for Mitrovic in search of his hat-trick when, on the slide, he couldn't quite get a toe to Timothy Fosu-Mensah's driven cross.
Hart then denied Schurrle with his legs when the hosts had two men spare when Mitrovic held the ball up and released at the perfect time.
Since Dyche took over in 2012, only once has a Burnley game in the Premier League produced six goals.
Well, you can now add their latest defeat to the 3-3 draw against Newcastle United at St James's Park on New Year's Day in 2015.
Hart, with Three Lions boss Gareth Southgate watching from the stands, made a stunning save to flick Mitrovic's effort on to the upright but Schurrle capped an impressive display when collecting the rebound and firing the ball inside the near post.