Slovenia rider Matej Mohoric, last year's junior world champion, caught the sole leader and pushed clear to win in 4:20.18. He finished three seconds clear of South Africa's Louis Meintjes with the select group in the peloton a further 10 seconds back.
Oram remained in the peloton until the final climb when the bunch split in an effort to catch the solo leader, eventually finishing four minutes behind the winner, with Smith a further 11 minutes back and Frame failing to finish.
"I really enjoyed the long climb, it was quite comfortable. But it is that steep kicker that took it out of me and a lot of other guys,'' said Oram.
"It meant when you come over the top you still struggled to find a wheel. That short steep hill was the one that got me with two laps to go. I chased and made it back on before the last long climb but I was cooked.
"I was feeling good to attack before the long climb but that steep one was a bit too powerful for me.''
The day also proved a hill too hard to climb for Pat McQuaid, who lost the controversial race for the presidency of the UCI to Britain's cycling leader Brian Cookson 24 votes to 18.
Tomorrow's racing focuses on the elite women's road race which is 140kms with an initial 57kms mostly flat from the spa town of Montecatini Terme with five laps of the Fiesole circuit in Florence.
Time trial silver medallist Linda Villumsen leads a talented BikeNZ team comprising her young Wiggle Honda teammate Emily Collins, London Olympian Jo Kiesanowski and talented Otago rider Reta Trotman.
The championships conclude with the elite men's race on Monday (NZT).