Antonio Conte's men went into the clash three points ahead of Roma at the summit following a run of six straight league wins.
The defending champions have not tasted defeat in Bologna since 1998, and made sure of another three points at the Stadio Renato Dall'Ara with a highly professional performance.
The visitors dictated play during the early stages and deservedly took the lead after 12 minutes, Vidal latching on to Federico Peluso's ball over the top to volley home moments after Claudio Marchisio had seen a goalbound effort cleared following another sparkling Juve move.
Conte's men looked to kill off the game and came close to a second five minutes later when Quagliarella had an effort deflected wide.
Attacking midfielder Alessandro Diamanti twice tested Buffon from range as Bologna looked to find a way back before half-time, but Juve's defence was rarely troubled.
Curci was beaten for a second time after 67 minutes, but Kwadwo Asamoah was adjudged to have been offside as he collected Llorente's neat throughball.
Despite Juve's clear superiority, Bologna should perhaps have levelled when striker Jonathan Cristaldo fired narrowly wide of the far post following an excellent counter-attack.
Marchisio and Llorente spurned further chances as the game headed to its conclusion, while Archimede Morleo headed over for Bologna.
