Georgia Williams has finished 12th.
The 27-year-old Aucklander Williams, who rides for the Mitchelton-Scott World Tour team, all-but matched her previous best of 11th two years ago in Austria.
It was 22-year-old Harvey's first time racing as an elite at the World Championships.
In the face of the coronavirus pandemic, the championships have been hastily re-arranged for Imola near Bologna after the original hosts in Switzerland were unable to stage the event under Covid regulations.
The event has been reduced to four days of elite racing only with the men's time trial Saturday, women's road race on Sunday (NZ time) and men's road race on Monday.
Rio Olympic road champion Anna van der Breggen took out the time trial world title after finishing runner-up on four occasions, with defending champion Chloe Dygert (USA) crashing out after recording the fastest time through the intermediate checkpoint.
Van der Breggen, who won the Giro Rosa last week, won in 40min 20.14sec to finish nearly 16secs clear of Swiss champion Marlen Reusser and 31 seconds fellow Dutch rider Ellen van Dijk, the 2013 time trial world champion.
Williams finished 12th to be 2min 16.70sec down on the winner with Harvey 2min 33.59sec down in 20th from the 50-strong starters
