Turkish President Recep Tayyip Erdogan suffered a bruising defeat on Sunday as the opposition candidate in Istanbul's controversial mayoral election re-run romped to victory. Ekrem Imamoglu had won the first mayoral vote in March by a slim margin of 13,000 votes over Erdogan's chosen candidate, Binali Yildirim, who contested the results and a new election was ordered. After being stripped of that victory over disputed claims of fraud, Imamoglu vowed a "battle for democracy" that turned him into a household name.