ASUNCIÓN, Paraguay — Paraguay’s governing Colorado Party won Sunday’s presidential election as Mario Abdo Benítez, a conservative former senator, defeated his rival, Efraín Alegre, a former lawmaker from a center-left coalition.

Mr. Abdo Benítez’s presidential bid evoked memories of Paraguay’s dictatorship from 1954 to 1989 because his father was the personal secretary of Alfredo Stroessner, the despotic military leader who ruled the small South American nation during those years.

The election extended the Colorado Party’s dominance in Paraguayan politics and solidified the rightward political shift in South America.

Mr. Abdo Benítez belongs to a more conservative wing of the party than the departing president, Horacio Cartes. His election follows transitions of power in Argentina, Brazil and Chile, where conservative or center-right leaders have defeated socialist parties in recent years.