"I have a partnership in a construction company and another one that makes windows and doors (so) it's hard to find sponsors and you really have to put your hand on your own pocket," said a surprised Aguilar, who is the first native of Chile on the European Tour.
The overnight runners-up are Sweden's Klas Eriksson and Jean Hugo of South Africa at 4-under 67.
There is a five-way tie for fourth place. England's David Dixon, Cedric Menut of France, Cesar Monasterio of Argentina, France's Adrien Mork and Juan Parron of Spain all shot 3-under 68.
Thursday's rain delay lasted more than two hours.
In 2005, Sweden's Joakim Backstrom earned his first career victory on the tour in a playoff against England's Paul Dwyer.