Chelsea, who spent over £170m on players over the summer, were the architects of their own downfall in the first half. Edouard Mendy gifted Leeds the opener by miscontrolling a backpass, allowing Brendan Aaronsen to pounce.
Four minutes later Raheem Sterling gave away a free-kick on the edge of the box, from which Rodrigo scored his fourth of the season after Jack Harrison’s delivery.
But Leeds also out-fought their opponents, particularly in midfield, in echoes of the famous historical battles between the two rivals.
And they sealed a first Premier League win over Chelsea in seven attempts, dating back to 2002, when Harrison scored after Daniel James’ cross was touched to him by Rodrigo.
An already raucous Elland Road was in disbelief at that moment; the home fans taunted their Chelsea counterparts and manager Jesse Marsch punched the air in wild joy.
There were chances for Chelsea. Sterling curled wide in the first minute and had a goal disallowed, while Marc Cucurella, signed for £62m, was also off-target twice.
But when Kalidou Koulibaly was sent off six minutes from time for a second booking, it summed up Chelsea’s afternoon, allowing Leeds fans to wallow in the elation of a superb start to the season as their team moved into second in the table.