The Chilean star hit early on from the penalty spot and doubled his tally in the first half, to help the Bianconeri open up an 11-point lead at the league summit.
Arturo Vidal was the hero for the Bianconeri, netting twice in the first half during a routine win that leaves the Turin outfit 11 points clear of Napoli at the Italian summit with just six matches left.
After crashing out of the Champions League in comprehensive fashion against Bayern Munich, Juventus was keen to put that disappointment in the rear-view mirror and continue the march to the Scudetto in the Italian capital. Against a Lazio side still in the hunt for a spot in the continental competition, Antonio Conte's men could not have asked for a better start.
Just seven minutes into the encounter, Mirko Vucinic escaped Lorik Cana only to be cut down in the box by a clumsy tackle from the center back. There was no doubt whatsoever about the penalty decision, and Vidal hit with authority to send Federico Marchetti and put his side into the lead. The goal immediately put the visitors in the ascendancy, as Lazio struggled to contain a vibrant attack throughout the first half.
Michael Ciani came to the rescue of his side to block from Claudio Marchisio after the midfielder latched on to Stephan Lichtsteiner's cross, while Vucinic went close to netting as his toe-poke from a low free kick forced an instinctive save from Marchetti. The home side challenged across the pitch, but its offensive efforts lacked clarity and focus and it rarely threatened Gianluigi Buffon between the posts.
Ciani once more saved a second goal when he made a diving intervention to block Vidal's shot, but Juventus was in control and it seemed just a matter of time before they were back on the scoresheet. Minutes after that chance. Vucinic's pass took a somewhat fortunate deflection in the box and, as the Lazio defense hesitated, Vidal took full advantage as he coolly finished past Marchetti. The Biancocelesti were sinking without a trace, and Champions League football looked a distant dream as they went into the break well behind the Serie A pace-setters.
A more determined host team came out for the second 45 minutes, and it nearly pulled one back just after the interval. A looping corner found the net of the stooping Ciani, and Buffon was forced to make an excellent save to keep his clean sheet intact as the ball spiralled towards the bottom-right corner. Instants later, however, Juve should have put the game beyond doubt with a golden chance.
Andrea Pirlo's free kick was saved by Marchetti, but the keeper could not hold on to the ball and it rolled loose with at least three black shirts chasing the rebound. Marchisio arrived first, but he misjudged the bounce, and off balance he sliced his shot well over to the bar in an awful miss.
Lazio was the next team to lament its luck in front of goal. Meeting a perfect cross from Antonio Candreva, Miroslav Klose got his free header all wrong and failed to hit the target.
After a thrilling start to the second period, the match soon lost its urgency with Juventus taking control, stroking the ball around the park and assuring victory. There was no way back for the home team, which slumped to defeat in front of its own fans to move further away from the European dream for 2013-14 and allow Inter and Roma to stay within striking range for a Europa League place.
Lazio remains in fifth place, eight points behind AC Milan for the final qualifying spot for the Champions League.