"This is a major defeat," said a senior Kremlin adviser, adding that the events of the last 24 hours bitterly remind Russian officials of the 2004 Orange Revolution, when Mr. Yanukovych saw his fraud-tainted election victory overturned after massive street protests brought a pro-western government to power.
"We made the same mistakes again" this time, said the Kremlin adviser, who spoke on condition of anonymity.
"For us, the conclusion is that the West succeeded in engineering a coup d'état."
Just what Russia's reaction to this apparent setback would be wasn't immediately clear.
Western officials seemed to be going out of their way not to provoke Moscow.
Some Kremlin aides in recent weeks had suggested Moscow could intervene to protect pro-Russian regions if Ukraine were to slide into civil war, but there is been no indication of high-level Kremlin support for such a move.
A pro-European government in Kiev, however, could find itself under heavy economic pressure from the Russians, who are a major fuel supplier and trade partner.
"They have a lot of economic levers they can pull," said Steven Pifer, a former U.S. ambassador to Kiev.
Analysts also warned that a major setback in Ukraine could provoke the Kremlin to crack down further on opponents at home, as it did after the Orange Revolution, which Russian officials perceived as a western-orchestrated takeover.
Many in the Kremlin continue to believe the West is seeking to engineer the same kind of revolution in Russia, advisers say.
"This is just the start of a major battle in the post-Soviet space," said one, referring to the latest events in Kiev.
Russian officials fumed publicly on Saturday, as news of the dramatic reversal in Kiev spilled out, and the Ukrainian parliament, which had swung behind the opposition, voted to remove Mr. Yanukovych from office and call new elections for May.
Even Mr. Yanukovych's political allies voted for the measures, as government authority melted away on the streets and protesters took over.
Mr. Yanukovych left the capital for his political heartland in the east of the country and denounced the day's events as a "coup d'état," but he seemed powerless to stop them.
By evening, the political nemesis Mr. Yanukovych had jailed—opposition leader and former Prime Minister Yulia Tymoshenko —had been released from prison and was cheered by thousands of demonstrators on Kiev's main square.
Russian Foreign Minister Sergei Lavrov worked the phones with his European and U.S. counterparts, according to statements from his ministry, telling them that "illegal extremist groups" had taken control over Kiev.
He called on his partners to pressure the opposition in Ukraine to return to the terms of the European-brokered political compromise signed on Friday, which called for Mr. Yanukovych to remain in office until new presidential elections late in the year.
But western capitals seemed unsympathetic, moving instead to work with the new opposition-led government.
Meantime, Russian President Vladimir Putin was silent on the events in Ukraine on Saturday.
But he did issue a series of statements congratulating Russia's Olympic team members on winning medals at this month's Winter Games in the Russian city of Sochi.
State television also focused on Olympic triumphs.
And in reports of events in Ukraine, program anchors used grave tones.
"Extremists have taken over in Kiev and the western regions of the country," said one on Rossiya-24, a state news channel.
When a Russian correspondent in Kiev described the "holiday-like atmosphere" among opposition supporters on the capital's main square, known as Maidan, the anchor quickly ended the live report, intoning, "the way Maidan looks now, it's not the best place to spend time."
Mr. Putin, however, has come from behind before in this unexpected geopolitical struggle over Ukraine, a country the size of France that is crucial to his ambitions to build a Moscow-led bloc of former Soviet states.
Three months ago, Mr. Yanukovych was on the verge of signing a trade and political partnership with the European Union that had been years in the making and would have posed a major obstacle to Mr. Putin's plans.
Instead, under heavy pressure from the Kremlin, Mr. Yanukovych reversed course at the last minute and pledged closer ties to Moscow, which in turn offered $15 billion in desperately needed loans as well as discounts on vital natural-gas supplies.
When Mr. Yanukovych's about-face set off substantial street protests in Kiev, the Kremlin accused the West of fomenting the demonstrations and supporting ultranationalist radicals.
And when the Ukrainian president offered concessions to the opposition last month, Moscow responded by suspending the release of the much-needed loans to Kiev.
As late as on Thursday, when bloody fighting between police and demonstrators in Kiev had riveted international attention, Russian Prime Minister Dmitry Medvedev warned Ukraine's government against behaving "like a doormat that people wipe their feet on."
Foreign Minister Lavrov blasted the EU for calling on Mr. Yanukovych to agree to early elections.
But that is just what Mr. Yanukovych agreed to in Friday's deal, along with constitutional changes that would reduce presidential powers in favor of the parliament.
He also agreed to the formation of a new coalition government that would likely to be led by his pro-European opponents.
But protesters proved unwilling to wait for new elections and Mr. Yanukovych fled the capital late on Friday.
Alexei Pushkov, chairman of the International Affairs Committee in Russia's parliament, on Friday called the situation "an ideal scenario for an Orange Revolution."
Hours earlier, it had said: "The West is giving Yanukovych a final push. It's not just a matter of Ukraine on its own. The ultimate goal, if you remove all the chaff, is to bring NATO closer to the borders of Russia."
On Saturday, Mr. Pushkov's Twitter feed noted that Mr. Yanukovych had fled the capital and protesters were roaming through his unguarded residence outside the capital.
"A pathetic end for a president," it said.
Source: The Wall Street Journal