Original: Yanukoych also served as the Prime Minister of Ukraine–twice–from November 21, 2002 to December 31, 2004 under President Leonid Kuchma and from August 4, 2006 to December 18, 2007 under current President Viktor Yushchenko, his main opponent in the 2004 presidential election, of which he was declared the runner-up.
Simplified: He again was Prime Minister of Ukraine from August 4, 2006 till December 18, 2007.