The opposition leaders appealed to the tens of thousands of demonstrators thronging the streets of the capital to defend their victory. Opposition leader Nino Burdzhanadze, the speaker of the outgoing parliament, proclaimed herself acting president until early elections in 45 days, and warned Shevardnadze's government to avoid bloodshed.
"The fate of our country is being decided now," said protest leader Mikhail Saakashvili. "We give guarantees to Shevardnadze that he will not be harmed, but let him know that if there is at least one shot fired at people, he will face justice."
Shevardnadze remained defiant, pledging "I will not resign" even as he was whisked away by bodyguards after hundreds of opposition demonstrators stormed the parliament building, interrupting the president in mid-speech.
"I can step down only within the framework of the constitution," Shevardnadze said. "It will depend on the parliament and the population, but everything has to happen within the constitutional framework."
This poverty-stricken ex-Soviet republic slid into its biggest political crisis in years after the Nov. 2 parliamentary elections, which brought tens of thousands of flag-waving demonstrators to the streets of the capital to protest what they claimed was a rigged vote.
But the roots lie in the deep economic misery of most of the population and the rampant corruption that has characterized Shevardnadze's reign. Respected outside of Georgia for his role in helping to end the Cold War as foreign minister under Mikhail Gorbachev, the 75-year-old Shevardnadze is considered a disappointing relic at home.
CBS News Correspondent Tom Fenton says Shevardnadze is now considered "damaged goods" in the West. Even the U.S., Fenton notes, has declared the November election a "massive fraud."
Shevardnadze's office called the opposition's actions — which also included seizing Shevardnadze's office and burning his office chair — an "armed state coup."
Speaking later from a government residence in Krtsanisi on the outskirts of Tbilisi, Shevardnadze sat outside on a white park bench surrounded by men in uniform and declared that "order will be restored and the criminals will be punished."
He signed a decree instituting a state of emergency in this ex-Soviet republic for 30 days. Shevardnadze gave the task of restoring order to the Interior and Defense Ministries.
Koba Narchemashvili, the Georgian interior minister, sitting at Shevardnadze's side, said that he would obey all the president's orders.
The parliamentary showdown came as tens of thousands of opposition protesters marched in Tbilisi, waving flags and chanting "Leave" and "Enough." Saturday was seen as the deciding day, because Shevardnadze had said that he would open the parliament no matter what and the opposition vowed to prevent that.
Minutes after Shevardnadze began his speech before the assembled parliamentary delegates, Saakashvili led hundreds of his supporters into the chamber. They overturned desks and chairs and leapt onto the podium.
"The velvet revolution has taken place in Georgia," Saakashvili said, referring to the practically bloodless 1989 uprising which ousted the Communists from Czechoslovakia and brought dissident playwright Vaclav Havel to power.
After taking over the parliament, the protesters moved on to occupy the president's office.
Burdzhanadze told CNN that "if the president will decide to call new parliamentary elections, presidential elections, I think it will be some way out of this crisis." Earlier, the U.S.-educated Saakashvili was quoted as telling CNN that Shevardnadze could remain in office if he calls early elections.
Shevardnadze has long claimed that he is key to maintaining stability in the turbulent, strategically located nation, which has been riven by a civil war and the secession of two provinces following the 1991 Soviet collapse. He has carefully cultivated western support and interest in his nation, which lies in the energy-rich Caspian region, and the United States helped train Georgian military forces to try to uproot extremists who had used Georgia as a jumping-off point for attacks in neighboring Chechnya.
As the protests built over the past two weeks, Shevardnadze's grip on the government seemed to be loosening and even his top security aide acknowledged that the election had been fraudulent. While there was no sign that the police and military had switched allegiance, they also didn't intervene to confront the protesters. Both Shevardnadze and the opposition took credit for the forces' restraint.
Some armored personnel carriers were shown on Georgian television taking up positions in front of Shevardnadze's residence, but authorities emphasized that they were not going to be used against the demonstrators.
"I am appealing to all police officers not to let Shevardnadze spill blood," Saakashvili said in televised comments. "There are your brothers and sisters here."
Vakhtang Khmaladze, a former parliament member and one of the authors of Georgia's constitution, questioned whether the opposition hadn't broken the law by naming Burdzhanadze acting leader. He said that like all members of the outgoing parliament, she lost her legislative seat as soon as the new parliament convened.
The opposition blamed Shevardnadze for forcing events, saying he had refused to recognize the situation developing in the country. As tension escalated Saturday, Shevardnadze appeared to soften his position. He acknowledged that there had been some breaches in the election, which the pro-Shevardnadze party won according to official results. "About 8 percent to 10 percent of the ballots were invalid," he said, but added that this should be dealt with in the courts.
According to final results, the pro-Shevardnadze For a New Georgia bloc came in first with 21.32 percent of the vote, while the Revival party, which sometimes has been critical of the government but sided with Shevardnadze in the present crisis, finished second with 18.84 percent.
Saakashvili's National Movement came in a very close third with 18.08 percent of the vote, while the Democrats who allied with Saakashvili got 8.8 percent.
The United States had strongly condemned the elections, and on Saturday State Department spokesman Richard Boucher urged all sides to try to avoid violence and negotiate a peaceful end.
"We call on all sides to refrain from the use of force or violence, and to enter into a dialogue with a view to restoring calm and reaching a compromise solution acceptable to all and in the interest of Georgia," he said.
Russia, which remains a key power in the region, dispatched Foreign Minister Igor Ivanov to Tbilisi, the Interfax news agency reported.
Shevardnadze complained Saturday against what he called biased media coverage of the Georgian elections and the ensuing political crisis. He urged global leaders not to encourage the opposition.