Italy bounced back from defeat to Australia as they cruised to a nine-try victory over Russia in their Pool C clash in Nelson.
The Azzurri, who led 38-7 at the break, registered scores through Sergio Parisse, Giulio Toniolatti (2), Tommaso Benvenuti (2), Edoardo Gori, Luke McLean, Alessandro Zanni and a penalty try, with fly-half Riccardo Bocchino, who limped off injured late on, adding four conversions.
To their credit Russia were much improved after the break, with Alexander Yanyshkin, Vladimir Ostroushko and Alexey Makovetskiy crossing for their tries.
Italy's first score arrived after just five minutes as captain Parisse was gifted too much space out wide and strolled over, with Bocchino adding the conversion.
Wing Toniolatti got his first Test try when swift hands sent him in at the corner, before Ostroushko's failure to deal with a Bocchino chip handed Benvenuti the simplest of scores for a 17-0 lead after 15 minutes.
The bonus point was secured after just 22 minutes as a quick line-out allowed Parisse the time to send Toniolatti in for this second of the night, with Bocchino adding his second conversion.
Italy were enjoying a crushing dominance in the scrums, and referee Wayne Barnes lost patience when Russia continually infringed close to the line and awarded the Azzurri a penalty try with Bocchino knocking over the simple conversion.
But Russia bravely battled back to score their first World Cup try.
Flanker Andrey Garbuzov made the initial break and a dangerous tackle by Fabio Ongaro, for which the Italy hooker was sin-binned, allowed them to retain field position, with replacement scrum-half Yanyushkin sniping over and Konstantin Rachkov converting.
But normal service was quickly resumed as McLean set up Gori to fend off some weak tackling to dot down under the sticks for a converted try and a 38-7 interval lead.
The tries kept coming as Benvenuti raced through to dot down his own grubber, but Russia were proving more competitive in the second half and they grabbed their second score of the night as Ostroushko showed McLean a clean pair of heals to score in the corner after more good work by the lively Yanyushkin.
McLean claimed Italy's eighth try with a fine solo break down the right before Russia centre Makovetskiy was sent in by a smart cut-out pass.
But Zanni had the last word as he rumbled over after another strong Azzurri scrum.