Lazio's win over Torino had seen the gap at the top of Serie A closed to one point prior to kick-off at Stade Luigi Ferraris, but Maurizio Sarri's side ultimately made light work of its host.
After a dominant first-half display failed to produce the goods, Juve made the pressure count early in the second period – Paulo Dybala opening the scoring before Ronaldo picked out the top right-hand corner of the net in sensational fashion.
Substitute Douglas Costa then put the visitors out of sight with an equally impressive strike before Andrea Pinamonti drilled in a 76th-minute consolation for Genoa.
Juve wasted little time in getting on the front foot, with Mattia Perin, on loan from the Bianconeri, pulling off two smart stops in quick succession to deny Ronaldo.
Perin's strong display against his parent club continued before the break, Adrien Rabiot heading straight at him from close range before the goalkeeper made an outstanding stop from a Ronaldo strike.
Juve's breakthrough finally came five minutes after the break, though, Dybala twisting his way clear of several defenders before lashing in a shot which Perin could only help into the net.
With Genoa's resolve broken, Juve had their second six minutes later, Ronaldo hammering home his 24th Serie A goal of the season from 25 yards out.
Costa curled in an exquisite third shortly after coming on as a substitute to wrap up Juve's third successive league win since the restart, though Genoa had the final say when Pinamonti finished from a tight angle.