Akhmar Zavgayev - closely associated with the republic's recently-elected President Akhmad Kadyrov - won 57.7% of the vote, reports said on Monday.
His closest competitor polled 12.7% of the vote in an election which saw a turnout of 83.46%.
There was, however, some confusion over the exact turnout with some reports on Sunday saying that Zavgayev had polled 100% of the vote before Itar-Tass corrected the figure.
The agency did not give details on the discrepancy between Sunday's and Monday's reported figures.
The reported turnout of 83.46% was far higher than the estimated 53% that showed up at polling stations across Russia as a whole.
In Chechnya's previous two elections this year - a referendum in March and a presidential poll in October - results had a distinct Soviet-era flavour.
In October, Moscow-backed Kadyrov won 81.1% of the vote on a reported turnout of 83.46% while the republic's capital Grozny was almost deserted on voting day.