Leeds were booed off by angry fans after this latest flop.
Sainsbury, who claims to have provided proof that funds are in place for a £25m takeover, has promised a £5m transfer kitty for manager Kevin Blackwell to spend, with a creative midfielder the priority.
Burnley, who had scored only twice away from home in eight games, doubled their away-day tally against a Leeds defence which looked unusually shaky.
Leeds couldn't have had a better start, conjuring up their quickest goal of the season when Jermaine Wright took just 12 seconds to celebrate his recall to the starting line-up with his first goal for the club.
Matthew Kilgallon played the ball forward, David Healy got the flick on and Wright shot past Burnley's stand-in keeper Brian Jensen in a flash.
But a Burnley side without five regulars recovered from their nightmare start and led just after the half hour.
The Clarets were gifted a tenth minute equaliser when Leeds defender Clarke Carlisle's backpass to keeper Neil Sullivan was too short and the mix-up was punished by Lee Roche, who collected his first goal since the start of last season and only the second of his career.
Worse was to follow for Leeds when they fell behind in the 31st minute. Sullivan did well to parry James O'Connor's header from Michael Duff's right-wing cross but 19-year-old Richard Duffy, making his first start on loan from Portsmouth, shot home from a narrow angle.
Leeds should have scored either side of half-time when Brian Deane had a free header, but the tall striker somehow sent the ball just the wrong side of the left post and early in the second half Julian Joachim hit the woodwork.
Robbie Blake was guilty of two equally bad misses with only Sullivan to beat, but Burnley ran out worthy winners.