Jonjo Shelvey notched a hat-trick for Blackpool and Lomana Lua Lua bagged a brace on his first start for the club, but despite banishing consecutive defeats with an at-times swashbuckling display, Ian Holloway's men had more than a little help from Rachubka.
Signed after his release by Blackpool this summer, Rachubka has endured a tough introduction to the United first team since Andy Lonergan suffered a fractured finger last month.
He was publicly backed by boss Simon Grayson after a mistake handed Coventry a 1-1 draw at Elland Road, but his shaky form has continued and his manager was in less conciliatory mood as 18-year-old Alex Cairns was handed his professional debut at the start of the second half.
Following Lua Lua's opener he spilt a routine catch, leading to Tom Lees' dismissal for deliberate handball and Shelvey's first from the penalty spot.
On-loan Liverpool playmaker Shelvey found his second goal amid more gift-wrapping as Rachubka dropped a Lua Lua shot at his feet.
Blackpool's leading lights added a goal apiece in the second half to make it an uncomfortable night for Grayson against the club he left in acrimonious circumstances in December 2008.
Despite starting on the back foot Leeds had the game's first opening when Blackpool goalkeeper Matt Gilks failed to hold a Robert Snodgrass free-kick from deep on the right flank.
Patrick Kisnorbo, starting in place of head injury victim Darren O'Dea, reacted quickest in a crowded penalty area but was thwarted first by Gilks and then centre-back Craig Cathcart.
Blackpool sprung up the other end to open the scoring as Stephen Crainey's delightful through ball released Shelvey in the inside-left position. His shot was parried by Rachubka towards Lua Lua who slotted home the 13th minute rebound.
The Seasiders doubled their advantage in farcical circumstances after 27 minutes. Rachubka dropped a routine cross from Alex Baptiste, Ludovic Sylvestre looked to pounce and Lees handled the goalbound shot to receive his marching orders.
Shelvey emphatically finished from the spot only for referee Roger East to rule out the effort for encroachment.
Unruffled, Shelvey calmly stroked his second effort beyond Rachubka's dive into the bottom corner, and the former Charlton youngster would benefit from an even simpler opportunity four minutes later.
Lua Lua drove speculatively from 25 yards and Rachubka spilt the shot, leaving Shelvey to round the prone, beleaguered goalkeeper and make it three.
Academy product Cairns was then given a raucous reception as he commenced his warm-up and a section of the home fans made their feelings clear 10 minutes before half-time, booing as Rachubka received a backpass.
The introduction of Luciano Becchio and Cairns briefly buoyed Leeds as the second half began.
Gilks rushed from his line to avert the danger as Adam Clayton burst through the Seasiders' defence, and top scorer Ross McCormack had a shot blocked, with optimistic penalty shouts falling on deaf ears.
Cairns received his second ovation of the night following a routine save from Shelvey, but he was left with no chance in the 65th minute when Lua Lua cut inside Paul Connelly and lashed into the top corner.
Substitute Martinez Angel then played through Shelvey to clinically complete his hat-trick with 12 minutes remaining.
Leeds' misery was complete, a six-match unbeaten home run left in tatters.