KIEV, Ukraine, Jumada I 28, 1435, Mar 29, 2014, SPA -- Ex-world boxing champion Vitali Klitschko, considered a strong contender to become Ukraine's next leader, upended the country's presidential race Saturday by announcing he will throw his support instead behind a billionaire candy maker, AP reported. Klitschko told his UDAR party that he plans to run for mayor of Ukraine's capital city, Kiev, paving the way for current presidential favorite, businessman Petro Poroshenko, in the May 25 vote. The move is likely to ensure that both men cement powerful positions in Ukraine's new government and block the chances of a full return to power from the country's former prime minister, Yulia Tymoshenko. The May 25 presidential election and Kiev mayoral vote are taking place against the backdrop of Russia's recent annexation of Crimea, Ukraine's dire economic straits and rumblings of discontent in the country's mainly Russian-speaking eastern provinces. Both Klitschko, 42, and Poroshenko, 48, played prominent roles in the months-long protest movement that led to the toppling of President Viktor Yanukovych in February. The demonstrations were sparked by Yanukovych's decision to back away from closer ties with the European Union and turn toward Russia but grew to encompass widespread discontent with corruption and the lack of democratic freedoms. "The only way to win is by nominating a single candidate from the democratic ranks," Klitschko said. "This should be a candidate with the greatest support from the people." Poroshenko, who also owns the popular Channel 5 television station and has served as foreign minister, already leads in the polls for the presidential election and is seen as likely to beat Tymoshenko, who declared this week that she will "be the candidate of Ukrainian unity." One analyst said Saturday's announcement was a strategic move by Klitschko. -- SPA 18:35 LOCAL TIME 15:35 GMT www.spa.gov.sa/1214792