Genoa are the only team have to beaten the reigning champions in Serie A this term thanks to a 1-0 win on home turf in October and Mbaye Niang almost gave them an early lead at the Juventus Stadium.
But Tevez, who notched a brace to help dump Borussia Dortmund out of the UEFA Champions League in midweek, illuminated the contest with a brilliant solo goal after 25 minutes.
It was not a flawless performance from the former Manchester City man, who saw a second-half penalty saved, but a third consecutive league win and a 17-point lead at the summit rarely appeared to be in doubt.
Roma, currently on a dismal run of form in second place, can close that substantial gap when they face Cesena on Sunday.
A slack pass from Leonardo Bonucci presented Niang with the opportunity to give Genoa a second-minute lead, but the forward curled narrowly wide from 20 yards.
Neither defence looked particularly assured during the opening exchanges and Facundo Roncaglia made a last-ditch block to deny Juventus striker Fernando Llorente.
Genoa felt they should have had a penalty in the 14th minute, but Diego Perotti was booked for simulation as home midfielder Claudio Marchisio went to ground.
Juventus were still struggling for fluency by the time a moment of magic from Tevez put them ahead.
The Argentina forward slipped past a pair of defenders on a typically bustling run before clattering home an angled shot via the underside of the crossbar for a 16th Serie goal of the season.
The visitors' early verve disappeared and it was almost 2-0 on the stroke of the interval - Giorgio Chiellini firing against the crossbar when Genoa failed to fully clear a corner.
Mattia Perin was injured in the build-up to the Chiellini chance, receiving lengthy treatment, and the when the Genoa goalkeeper punched a cross away in clear discomfort six minutes after the restart he was replaced by understudy Eugenio Lamanna.
And, as he did after emerging from the bench against Roma in December, Lamanna thwarted the opposition from the penalty spot - Tevez's 62nd-minute effort struck at helpful height following Roncaglia's trip on Roberto Pereyra.
Genoa's best chance for a leveller came 10 minutes from time, as Andrea Barzagli cleared brilliantly to deny Perotti at the far post, but they could not find a way through and Juventus retaining their crown appears an increasing formality.
