Armenia's governing Civil Contract party won an election seen as a test of its handling of a peace deal with Azerbaijan and its growing turn to the West, despite what international election observers called blatant interference and pressure by Russia.

Prime Minister Nikol Pashinyan leads polls ahead of Sunday’s high-stakes vote, seeking a mandate for sweeping constitutional reforms despite intensifying Russian trade blockades.

Prime Minister Nikol Pashinyan and his governing party are looking for a strong mandate for a new geopolitical course for Armenia. The opposition includes some parties that are…