Andrea Belotti found the net few minutes after the duel was underway but Pasquale Fazio soon levelled proceedings.
The Italian added his second three minutes before the half-hour mark and Alex Berenguer found his way past his marker to net the third goal for the Stadio Olimpico Grande outfit.
Belotti completed his hat-trick in the 39th minutes to take the game beyond the reach of their guests.
Obi breached the defence of Alessandro Calori‘s men two minutes before the half-time interval.
Iago Falque and Lorenzo De Silvestri compounded the woes of Stadio Polisportivo Provinciale giants as they marked a goal each before the clash came to an end.