The young Swede won three of the five special stages in his Ford Fiesta R2 to build a 27.0sec lead over Jose Suarez. Marius Aasen won the other two tests and the Norwegian lies third, 32.8sec behind his fellow Scandinavian.
“We had a very good day, despite starting with a little trouble on SS1 where we caught two cars in front of us. Otherwise everything worked well and our Ford Fiesta R2 stayed in perfect condition,” said Tidemand.
Drivers from eight different countries are competing in identical Fiesta R2s in the first of six rounds, all of which support the FIA World Rally Championship
The series, which has been upgraded from the FIA WRC Academy to full world title status, is regarded as the first opportunity for potential stars of the future to display their talent on the world stage.
Aasen was quickest out of the blocks to win the opening test, but Tidemand stamped his authority in the next stage to open a 10.9sec advantage over Suarez.
Although Aasen was fastest in SS3, he only regained two-tenths of a second and Tidemand extended his advantage over the final two tests.
The top three drivers pulled clear of the rest of the pack. Turk Murat Bostanci lies fourth, 2min 02.2sec off the lead, with Martin Koci and Andreas Amberg completing the top six.
The only retirement was Estonian Sander Parn, who stopped in the opening stage after losing a wheel.
The Junior WRC category ends after tomorrow’s second leg, comprising six stages and 158.54km.