Elections to choose a new leadership in the Georgian province of Ajaria will take place next month, following the resignation of its rebel leader.
The events in Ajaria are being called a second rose revolution
After two nights of street protests calling for Aslan Abashidze to step down, he quit and flew to Moscow.
Georgian President Mikhail Saakashvili has said he will not ask Russia to extradite Mr Abashidze, who is accused of corruption and human rights abuses.
Georgian troops have moved into the regional capital to take control.
The BBC's Natalia Antelava in Batumi says it is party time in Ajaria's capital.
Hundreds of people are out in the streets congratulating each other, she says.
Speaking earlier in Batumi, Mr Saakashvili told a jubilant crowd that they were heroes.
He thanked his Russian counterpart, Vladimir Putin, for helping to solve the crisis.
Correspondents say Mr Abashidze is expected to ask for asylum in Russia, his long-time ally.
The collapse of Mr Abashidze's rule came after a month-long confrontation, in which his armed supporters blew up bridges linking Ajaria to Georgia proper.
Mr Abishidze had said he had "no intention" of quitting Ajaria.
Population: 400,000; overall population of Georgia: 5 million
Depends on income from transited goods, its port shipping about 200,000 barrels of oil a day
Has run its own affairs for years, withholding tax payments from central government in Tbilisi
Ajarians are ethnic Georgians but mostly Muslim, unlike the majority in the Orthodox Christian state
However, pressure came to a head on Wednesday when the president declared direct presidential rule and offered Mr Abishidze safe passage abroad.
Announcing the rebel leader's resignation on TV on Wednesday night, Mr Saakashvili said he wished to mark "the beginning of Georgia's unification".
"Georgia will be united," he declared, in an apparent reference to two of the tiny Caucasus republic's other regions, South Ossetia and Abkhazia, which have been out of Tbilisi's control for years.
The BBC's Chloe Arnold in Tbilisi says Georgians are calling the events of the last few days their second 'rose revolution'.
The first took place last November when Mr Saakashvili led a peaceful uprising to overthrow his predecessor, Eduard Shevardnadze. He took office in January after a landslide election win.
Mr Abashidze was a Soviet-era politician who strongly opposed the Western-leaning Mr Saakashvili.
The crisis aroused the concern of Russia, Europe and the US, all of whom consider the Black Sea state to be of key strategic importance.
The US is backing the construction of a multi-billion dollar pipeline to transport Caspian Sea oil through the volatile region to the international market.
Russia, a giant among the world's oil exporters, retains a military base in Ajaria, where there is a substantial ethnic Russian community.
Washington welcomed "the peaceful restoration of Tbilisi's authority" and called it a
"historic day" for Georgia.