Kauppi, who runs for Asikkalan Raikas in Finland, finished half a minute ahead of the young Swede Tove Alexandersson over the 5.5 kilometre course.
Pre-tournament favourite Simone Niggli of Switzerland finished fourth.
The win gave Kauppi her fourth World championship gold. The world orienteering championships continue with the long distance event, before the relays on Saturday.
Yle will broadcast Saturday’s competition.