Reigning champion Josh Files claimed his fifth pole in a row during qualification but he was powerless to stop Nogues, who roared into contention from fourth on the grid.
Nogues triumphed in what was a very competitive race ahead of Files (Team Pyro) and Mikel Azcona (Automobil Club Zaragoza).
In the second race, Nogues edged Eric Trémoulet (Vic’Team) in a thrilling battle to double up for the weekend.
Nogues clinches title in Jerez
Just 0.068s separated the two at the finish line with Massimiliano Pedalà (Composit Motorsport) completing the podium with an even smaller margin, 0.012s ahead of Azcona.
On Friday, Files had got his quest for another title off to the perfect start on the same track where he won top honours last November. The Englishman set best time in the collective test, ahead of 2013 championship runner-up Pedalà and Azcona.
2012 Eurocup Clio champion Nogues was quickest in the morning session.
Nogués eyes history in Andalusia
Azcona grabs maiden win, Nogues extends lead