Paulo Dybala's hat-trick masked a worrying early collapse from Juventus as the reigning Serie A champions fought back to beat Genoa 4-2 at the Marassi.

Within a matter of seconds following kick-off Miralem Pjanic somehow managed to put the ball through his own net when attempting to clear Goran Pandev's cross.

Juve's woe deepened when Genoa won a penalty through the video assistant referee, with Andrey Galabinov converting.

Dybala launched the Bianconeri comeback with a scorching strike from distance that made it 2-1 after only 14 minutes, then on the stroke of half-time Juve were awarded a spot-kick.

It was all square at the break as Dybala took full advantage following another VAR decision.

Despite their poor start Juve were on top and heading for victory by the 61st minute, as former Chelsea winger Juan Cuadrado controlled Mario Mandzukic's assist before slamming home.

Then, with time running out, Dybala completed his treble to assuage fears Juve are set for a season of struggle as they pursue a seventh straight Scudetto.

Godfred Donsah fired Bologna to their first win of the season at the expense of promoted Benevento, who agonisingly lost 1-0 at the Stadio Ciro Vigorito.

Fabio Lucioni saw his second-half stoppage-time effort for Benevento ruled out for offside by VAR, so the southerners' quest for a first ever top-flight point continues against Torino next month.