Troubled Manchester United crashed to a third defeat in their last four Premier League games as Burnley powered to a surprise 2-0 win at Old Trafford on Wednesday.
Ole Gunnar Solskjaer's side were rocked by Chris Wood's first half opener before Jay Rodriguez scored with a superb strike after the break.
It was a dismal display from fifth placed United, who are in such poor form that there will be fresh questions about Solskjaer's job security in the coming days.
Solskjaer could have no complaints about a result that laid bare everything wrong with a rudderless team lacking steel in defence, creativity in midfield and a cutting edge up front.
United trail six points behind fourth placed Chelsea but, given how they have struggled so often this season, the only surprise is that the gap isn't bigger.
Stunned by their second home league defeat this season, United's tally of 34 points is their lowest after 24 matches of a top-flight season since 1989-90.
United must regroup to avoid more misery in the FA Cup fourth round against Watford or Tranmere on Sunday before they head to Manchester City looking to overturn a 3-1 first leg deficit in the League Cup semi-finals next Wednesday.
If United are knocked out of both cup competitions, Solskjaer is likely to find the patience of supporters who idolised him during his playing days will dwindle even further.
Those that hadn't already fled before full-time made their feelings known as they booed United off at full-time.
Losing to a Burnley side who had won one of their last 30 Premier League matches against established top-six opposition was another blow for United fans already depressed by the prospect of bitter rivals Liverpool winning the title for the first time since 1990.
The gap between United and runaway leaders Liverpool stood at 30 points after Sunday's defeat at Anfield and there is no sign of Solskjaer bridging the divide any time soon.
- United made to pay -
He hasn't been helped by an injury to United's top scorer Marcus Rashford, who has been ruled out for up to three months with a stress fracture in his back.
With Rashford sidelined, the sight of France forward Anthony Martial in pain on the turf after an early aerial challenge would have been a huge concern for Solskjaer.
Martial was eventually able to gingerly rejoin the fray, but sliced horribly wide with the goal at his mercy when he was picked out by Aaron Wan-Bissaka.
Juan Mata fared no better with an embarrassing miscue when he tried to meet Wan-Bissaka's cross with a close-range volley that ended up hitting his own leg.
Daniel James went closer with a towering header that belied his diminutive size and forced Nick Pope to tip over.
United were made to pay for their profligacy as Burnley snatched the lead in the 39th minute.
Exposing United's weakness at set-pieces, Ben Mee rose above Nemanja Matic and nodded down to New Zealand striker Wood, who got in front of the ponderous Harry Maguire to fire home from close-range.
Wood's 10th goal of the season was the first time Burnley had scored in the first half of a Premier League game in their last 12 games.
United had now kept just four league clean-sheets all season and Solskjaer responded by introducing teenage forward Mason Greenwood at the interval.
They still looked nervous and Fred was fortunate not to concede a comical penalty after handling when he tripped in his own area.
Just when Solskjaer thought it couldn't get any worse, United hit rock bottom in the 56th minute.
A quick exchange of passes carved open United's defence and found Rodriguez, who ignored the tight angle to unload a blistering strike that cannoned down off the bar and over the line to clinch Burnley's first win at Old Trafford since 1962.