PORT HARCOURT, Nigeria, April 13 (Reuters) - Nigeria's ruling People's Democratic Party (PDP) won the governorship election in oil hub Rivers state with 1,029,120 votes, the electoral commission in state capital Port Harcourt said early on Monday. The candidate of the All Progressives Congress (APC), the party of president elect Muhammadu Buhari, received 124,896 votes, the commission added. Incumbent governor Rotimi Amaechi defected from the PDP to the APC two years ago and has been feuding with President Goodluck Jonathan ever since. Tensions were high during the weekend polls and voting had to be extended in some districts after violence and theft of electoral materials marred the process.