Fisher-Black was second, with Garcia, bidding to become the oldest road world champion at 41, third, 26 seconds back. Switzerland’s Elise Chabbey was fourth at 41 seconds.
The leading favourites trailed home in the chasing group after being caught out and leaving their response too late.
The brutal race featured 11 laps of the circuit with 3350m of climbing.
Fisher-Black said it was a strange race.
“It didn’t really feel like we were racing, the race didn’t feel hard at all.
“Once I saw I was in a position to win I knew where my strong points were and tried.
“But Magdeleine, I didn’t even anticipate that she would try on the cobbles but she rode away from me and I have to give it to her, she was the strongest rider.”
Ella Wyllie was 24th.
Fisher-Black won the under-23 world title in Australia in 2022.
Earlier this week, fellow New Zealander Nate Pringle took silver in the men’s under-23 time trial at the World Championships.
- RNZ