Leeds’ high-energy start proved lucrative, as with just five minutes on the clock Jaka Bijol put the hosts in front. It was a goal that owed much to the delivery of Anton Stach, with his corner rocketed into the near post where Bijol added the finishing touch.
Ten minutes later, they wasted a similar opportunity, with Pascal Struijk heading harmlessly wide on this occasion.
Chelsea were below-par and second-best, but Enzo Maresca’s men looked to have at least weathered the storm by the half-hour mark, beginning to dominate possession, albeit without creating a chance of note.
However, the hosts' frantic press reaped rewards again just two minutes before the break.
Enzo Fernández gave possession away cheaply, and from the breakdown Ao Tanaka thundered in an unstoppable shot from the edge of the area that flew past Robert Sánchez and into the bottom corner.
A potentially game-changing 120 seconds at the start of the second half paved the way for a Chelsea revival, as Sánchez stood tall to stop a smart Lukas Nmecha half-volley, before the away side grabbed themselves a lifeline up the other end.
A sweeping move allowed Gittens to get to the Leeds’ byline, and his cross to the back post found half-time substitute Pedro Neto, who took a touch and poked home.
Enzo Maresca hoped that the introduction of Cole Palmer, returning after a two-month lay-off, would be the catalyst for a Chelsea comeback, but the England international fired wide when found by an Alejandro Garnacho cross.
Ultimately, Chelsea would rubber-stamp the defeat themselves, as Tosin Adarabioyo inexplicably allowed Noah Okafor to steal in and tee up Dominic Calvert-Lewin. The England forward tapped home to seal another sorry night at Elland Road for the London side, who have now won just six of their 49 historical away league games against Leeds.
The result leaves the Blues fourth in the table, being brought back down to earth following their impressive result against Arsenal at the weekend, while Leeds are now three points clear of West Ham United in 17th thanks to this triumph.
Flashscore Man of the Match: Anton Stach (Leeds United)