Paulo Dybala vindicated Maurizio Sarri's decision to introduce him for the underwhelming Cristiano Ronaldo as the Argentina international clinched underwhelming Juventus a slender 1-0 win over AC Milan on Sunday.

Sarri's men were well below par for the visit of Stefano Pioli's Milan and Ronaldo was no different, as the Portugal star failed to inspire an Old Lady attack that looked bereft of creative ingenuity until matchwinner Dybala replaced the five-time Ballon d'Or winner.

Belying the form table, Milan looked considerably more fluent and inventive in attack during the opening 45 minutes, but questionable finishing and a wonderful save from Wojciech Szczesny prevented them going into half-time ahead.

Juve remained short of ideas going forward initially in the second period and that resulted in the withdrawal of Ronaldo – who was also hooked in the Champions League against Lokomotiv Moscow.

While the Portugal captain looked utterly unimpressed as he headed straight down the tunnel, Dybala made the difference late on with a fine goal to retain Juve's status as Serie A pacesetters.

Milan should have taken the lead with 18 minutes on the clock, but Krzysztof Piatek miscued his header from Suso's excellent delivery from deep, before Szczesny thwarted Lucas Paqueta's nodded effort.

It took Ronaldo until the 42nd minute to threaten the Milan goal, but his 25-yard strike was easily kept out by Gianluigi Donnarumma.

Sarri's response to Juve's ineffectiveness in front of goal was to withdraw Ronaldo for Dybala before the hour, while Douglas Costa – the hero in Wednesday's 2-1 win in Moscow – came on soon after.

The Brazilian went as close as any of his team-mates with a 30-yard strike that Donnarumma stopped, before Blaise Matuidi curled just off target.

But fittingly it was Dybala who got the decisive goal, as he played a one-two with Gonzalo Higuain on the edge of the box and then swept home right-footed 13 minutes from time, confirming an undeserved defeat for Milan, who have not won at Juve since March 2011.

What does it mean? Juve remain top as Ronaldo's mortality becomes clear

Inter's 2-1 comeback win against Hellas Verona put Antonio Conte's men top and that looked to be where they would stay until after the international break before Dybala's strike.

But arguably more significant than the result is Ronaldo's status in the squad. Having spent much of his career as an untouchable, that no longer appears to be the case.

Szczesny gives Juve a hand

While Dybala was undoubtedly vital to victory, it is fair to say Juve owe much thanks to Szczesny in goal. The Poland international was dependable on every occasion and had he not been at this level Milan probably would have won.

Ronaldo fades into the background

With just one shot and a single key pass to show for his efforts, there is no doubt Ronaldo was not missed when he made way. Suddenly the hosts had more energy and impetus in attack, not usually something one could say about a team that hooks Ronaldo.

What's next?

After the international break, Juve face a tricky trip to Serie A's most prolific team Atalanta, while Milan host Napoli and former Rossoneri boss Carlo Ancelotti.