PARIS — Corsican nationalists won almost half of the vote in the first round of the French Mediterranean island’s territorial election on Sunday, a landslide likely to fuel local calls for greater autonomy from Paris.

The ticket led by the “autonomist” leader Gilles Simeoni won about 45 percent of the votes for a newly created, more powerful local assembly, according to final Interior Ministry results. A second round of voting will be held next Sunday.

President Emmanuel Macron’s ticket came in fourth, with about 11 percent of the vote. In the April and May presidential elections, Mr. Macron did far worse in Corsica than he did nationally.

Mr. Macron’s Republic on the Move party said in a statement Sunday that the vote showed Corsicans’ loss of confidence in the central government. The party pledged to try to rebuild trust everywhere in France.