Juventus outclassed Siena with a convincing 3-0 victory to go seven points clear at the top of Serie A.
Stephan Lichtsteiner put the champions ahead with a lucky effort before the break.
Andrea Pirlo caught Siena cold with a quick free-kick to Sebastian Giovinco, who rifled in a second to settle Juve's nerves.
Innocent Emeghara and Christian Terlizzi each hit the woodwork for Siena before Paul Pogba secured the win with a fine strike from distance late on.
Friday's game between Serie A's top two, Juve and Napoli, looks set to be Napoli's last chance to catch Antonio Conte's side. Napoli visit Udinese on Monday in the hope to close the gap to four points, while Juve had to make sure they did the job against Siena on a bitterly cold Sunday afternoon in Turin.
And it was one-way traffic for much of the contest. Inspired by Mirko Vucinic, Juve were at a stroll and could have ended the first half at least 3-0 ahead.
With Siena sitting deeper and deeper, Juve almost exposed them when Pogba and Vucinic combined well but Vucinic's flick back towards the former Manchester United midfielder was cut out, with Giovinco unmarked at the far post.
But with Kwadwo Asamoah on the left and Lichtsteiner on the right, Juve were always a threat going forward, and the latter gave the Bianconeri the lead on the half-hour mark.
The Swiss international raced forward to latch onto Vucinic's delicate clipped pass, and Siena goalkeeper Gianluca Pegolo came out to block the effort, but he batted the ball against Lichtsteiner and the ball ricocheted into the net. While it was a fortuitous goal from a Juve perspective, it was no less than they deserved.
Juve threatened to add to their lead before the break but Siena held firm and the visitors started the second half brightly. But the Juve defence were never unduly worried and it was only a matter of time before Juve put the game beyond the Serie A strugglers. Pirlo almost claimed the all important second goal with a sensational chip from 20 yards that just dropped the wrong side of the far post.
But they were eventually rewarded for their dominance and Pirlo played a key role in the goal. His quick free-kick caught Siena cold and Giovinco latched onto it before lashing the ball into the roof of the net, settling any nerves inside the Juventus Stadium.
Siena responded with their best effort of the game as Emeghara found space in the box but his goal-bound header was tipped onto the bar in stunning fashion by Gianluigi Buffon. Boosted by that chance, Siena enjoyed a good spell and centre-back Christian Terlizzi also hit the woodwork, finding the post from 20 yards with a low drive.
But with the game approaching the final minute, Pogba put the gloss on the win with a fine individual strike from distance, shifting the ball onto his right foot and finding the bottom corner from 20 yards.
Napoli can close the gap to four points with a victory over Udinese, and to one point if they can find a way to beat Juve on Friday. But Juve will feel confident they have taken an important step towards a second successive Scudetto.