Italy winger Louis Lynagh contributed to a remarkable comeback that saw the Azzurri beat Scotland for the first time in nine years, moving them above Australia.
Scotland's Six Nations campaign unravelled in disastrous fashion in Rome as they crashed to a first defeat against Italy since 2015.
Italy were within the width of a post of the biggest upset in Six Nations history as they drew 13-13 against 14-man France in Lille.
Harlequins winger Louis Lynagh could make his Test debut for Italy against France in the Six Nations next week.
Ireland continued their Six Nations title defence with a resounding 36-0 bonus-point win over Italy in Dublin where Jack Crowley claimed his first senior try.
England survived a scare at the Stadio Olimpico to launch their post-World Cup rebuild with a 27-24 victory over Italy in their Guinness Six Nations opener.