Jeffery Lea Hogg of Kensington was convicted in 2012 and later sentenced to 27 months in prison.
In a split decision in August 2013, the Prince Edward Island Court of Appeal threw out the conviction and ordered a new trial.
The appeal court found that the trial judge erred in weighing the evidence.
The Supreme Court, in a rare ruling from the bench today, overturned the court of appeal and restored the original conviction.
Written reasons for the decision were not immediately released.