Massimiliano Allegri's men were comfortable throughout in Turin and kept their healthy nine-point lead at the Serie A summit following Napoli's win over Lazio, though things would have been even more comprehensive had Ronaldo been accurate from the spot.
Although the visitors started positively, Juve still managed to take an early lead in style through Costa, before Can made it 2-0 late in the half – the Germanyinternational scoring for the first time since joining from Liverpool.
Ronaldo wasted the chance to extend the advantage in the 52nd minute, though there was never any risk of a fightback, as the plummeting Flying Donkeys suffered their 11th defeat of the season to remain nine points adrift of safety, with Rugani wrapping things up late on.
Chievo kept Juve at bay for just 13 minutes, as Costa took things into his own hands with a darting run in towards the centre, before drilling a left-footed drive into the bottom-right corner from 30 yards.
Juve stepped things up another notch after a bit of a lull – Stefano Sorrentino making an unorthodox save with his right foot to divert Federico Bernardeschi's deflected 20-yard strike off target.
He was helpless to deny Can just before the break, however, as the German opened his Juve account with a calm finish from just inside the area after an incisive run and pass from Paulo Dybala.
Juve should have extended their lead early in the second half, but Sorrentino produced a fine save to keep Ronaldo's penalty out after a Costa strike had been handled by Mattia Bani.
Sorrentino was eventually beaten for a third time in the 84th minute, however, as Rugani met Bernardeschi's left-wing free-kick delivery to head in.
Juve still in complete control in Serie A
There is often a little extra pressure applied when the league leaders play later than the chasers, as was the case here, but Allegri's men never looked fussed. They were in charge from the start and never threatened to increase Napoli's title hopes, Juve restoring their nine-point lead.
Dybala supplies the craft
It has been a difficult season for Dybala, who has scored just two goals in Serie A. However, on Monday he showed why there is so much more to his game than scoring, as he set up both Juve goals.
A day to forget for Ronaldo
While he was not exactly terrible, it was certainly not one of Ronaldo's better performances for Juve. Although he was lively enough, he did not seem at his sharpest and he saw a penalty saved. With the Portugal star set to appear in court in Madrid on Tuesday due to alleged tax offences, you can understand if he was a little distracted.
