Their clash with unbeaten Roma - their nearest rivals in second - brought three goals and two red cards, with the strikes going to Juve and the dismissals to the visitors as Rudi Garcia's men were turned over 3-0.
Roma's 10 successive wins were a distant memory on Sunday night as Arturo Vidal, Leonardo Bonnuci and Mirko Vucinic scored for the home side.
Vucinic's goal came from the spot at the end of a shocking minute for Roma which also saw Daniele De Rossi and Leandro Castan sent off inside 86 seconds.
Elsewhere, Gonzalo Rodriguez scored the only goal of the game to earn Champions League-chasing Fiorentina a narrow 1-0 win at home to Livorno.
Rodriguez headed home a corner midway through the second half to keep the hosts in contention for a top-four place.
The win came at a cost, though, as La Viola striker Guiseppe Rossi suffered a possible injury setback after hurting his knee during the victory.
La Viola confirmed the Italy international had suffered a "sprain" to his right knee, the joint in which he has twice damaged cruciate ligaments.
In the other game, Mauricio Pinilla missed a second-half penalty as Cagliari were held to a goalless draw by strugglers Chievo.