The ex-Soviet state's bloody three-month crisis culminated in a dizzying flurry of historic changes over the weekend that saw parliament oust the pro-Russian Yanukovych and call a presidential election for May 25.
Lawmakers then went a step further by approving the release from her seven-year jail sentence of former prime minister Yulia Tymoshenko -- a star of the 2004 Orange Revolution who was thrown behind bars less than a year after Yanukovych came to power in 2010.
The constitutional legitimacy of parliament's actions remains an open question and Yanukovych vowed in a taped interview to fight the "bandits" who now claimed to rule Ukraine.
But Yanukovych's grasp on power was in limited evidence in Kiev today as the city's police presence vanished and protesters took control of everything from traffic management to protection of government buildings after a week of bloodshed that claimed nearly 100 lives.
The United States vowed to drum up financial help that could help pull Ukraine out of a crisis that erupted in November when Yanukovych spurned an historic EU trade deal and secured a USD 15-billion bailout for the struggling nation of 46 million people from old master Russia.
Lawmakers voted today to name close Tymoshenko ally Oleksandr Turchynov -- himself only appointed as parliament speaker yesterday in place of a veteran Yanukovych supporter -- as interim president with the task of forming a new government by Tuesday.
Turchynov immediately vowed to draw up a "government of the people" and urged leading lawmakers to create a new parliamentary majority that could swiftly approve reforms that had stalled under Yanukovych.
"We have until Tuesday," the 49-year-old interim leader said.
New interior minister Arsen Aviakov announced the launch of a probe into police involvement in the "execution" of protesters in a week of carnage that turned the heart of Kiev into a war zone.
Yanukovych was dealt another embarrassing blow when his own Regions Party issued a statement condemning him for issuing "criminal orders" that led to so many deaths.
Parliament also voted to dimiss Ukraine's Foreign Minister Leonid Kozhara after sacking the federal police chief and prosecutor general yesterday.