The Clarets youngsters fell to a late 2-1 defeat as Hull City came from behind to snatch victory.
Full back Jordan Cropper had put Burnley ahead before Keane Lewis-Potter levelled things for the Tigers before half time.
And with just five minutes to go Josh Thacker stabbed the ball home to inflict heartbreak on the Clarets, who were again under the guidance of assistant coach John Townson, with Danny Cadermarteri currently out working with the England U18s in Qatar.
Townson said: “We feel we've been done today and fair play to Hull, who worked hard for what they
“In both boxes we lost the game. Our approach play was very good but our quality of cross or final ball was lacking.
“When a good ball did go in the box we didn't look like we'd get hurt to get on the end of it. We made one error in the second half and they punished us from the set piece in probably one of only two or three attempts on goal.
“We must learn from it, put it to bed on Thursday in the analysis and prepare for a big game on Saturday at home to Crystal Palace."
Burnley started well and twice came close, with Jordan Barnett and Craig Ellison both seeing efforts just wide.
However, the Clarets did take the lead with 34 minutes gone, as Cropper was brought down in the area and stepped up to slam the ball home.
But within minutes the Tigers had their equaliser, as Lewis-Potter slotted the ball home from close range to draw things level heading into the break.
The visitors pushed for the next goal after the restart and Marley Blair came close turning a cross just wide at the back post.
But despite Burnley’s best efforts at grabbing the winner, it was Hull who struck as Thacker did well to turn and finish in the area from a corner with just five minutes to go.
BURNLEY: Bruce, Cropper, Trialist, King, Glennan, Barnett, Yari, Kershaw, Moss, Blair, Ellison.
Subs: Stone, Layton, Meredith, Jumeau, Harris.