MOSCOW—Armenia’s acting Prime Minister, Nikol Pashinyan, kept power in a parliamentary election that boosted his authority despite being widely blamed for a military defeat last year in the Nagorno-Karabakh enclave, results showed on Monday. Pashinyan’s Civil Contract party won 53.92 percent of votes cast in Sunday’s snap election, according to preliminary results on Monday. Former President Robert Kocharyan’s Armenia Alliance trailed on 21.04 percent, and questioned the credibility of the result, the Interfax news agency reported. The government called the election to try to end a political crisis that began when ethnic Armenian forces ceded territory to Azerbaijan in and around Nagorno-Karabakh in six weeks of fighting last year. The hostilities caused international concern because the wider South Caucasus region is a corridor for pipelines carrying natural oil and gas to world markets. It is also a geopolitical arena with Russia, the United States, the European Union, and Turkey all …