First results from Georgia's presidential election show the man who toppled President Eduard Shevardnadze gaining up to 97% of the vote.
Saakashvili says he is ready to deal with Georgia's "mess"
The figure is based on returns from 25% of the country's polling stations, but lends weight to exit polls indicating a landslide win for Mikhail Saakashvili.
He claimed victory overnight and told the BBC his priority was to halt corruption and attract investment.
Analysts say he faces an uphill battle because the country is in a mess.
Crime is rampant, unemployment is high, state coffers are empty and power shortages occur even in the capital, Tbilisi.
Mr Saakashvili, 36, has warned of spending cuts and called on the Georgian people to be patient - but analysts say the public will want to see results quickly.
In one vote of confidence, monitors from the Organisation for Security and Co-operation in Europe said Sunday's poll was an improvement on previous fraud-ridden Georgian elections.
"This was not a perfect election by any means, but there were many, many positive things that we observed and we are proud to report on," said Bruce George, a British MP who headed the 450-strong observer mission.
"He has inherited a very difficult legacy," Archil Gegeshidze, an analyst at the Georgian Foundation for Strategic and International Studies told the Reuters news agency.
"Clearly he has been given a very strong 'carte blanche' from the people, but this will not be on offer indefinitely."
Half of the population live on less than $4 (three euros) a day, while pensions are often as low as $7 (5.5 euros) a month.
The untaxed shadow economy is estimated to be twice the size of the legitimate economy.
There is also a large backlog in payments to public sector workers and a huge foreign debt of $1.7bn.
In foreign relations, Mr Saakashvili has said he wants better relations with Europe and the US and with Russia too.
"One of the fundamental priorities of the new leadership will be the establishment of much closer, warmer ties with the Russian Federation," he said.
But analysts say Russia is keen to keep Georgia in its sphere of influence, and is wary of the pro-Western Mr Saakashvili.
Other major problems inherited from Mr Shevardnadze include frozen conflicts with the breakaway regions of Abkhazia and South Ossetia.
Neither has recognised Tbilisi's authority for more than a decade.
A third region, Ajaria, threatened to boycott Sunday's election, but changed its mind at the last minute.
Mr Saakashvili represents Georgia's main opposition blocs, which joined forces to topple Mr Shevardnadze, after flawed parliamentary elections early in November.
Critics accuse him of being a populist, and point out that he lacks experience.
Results from Sunday's election were slow coming in because of bad weather.
In the remote Kodori gorge, in the west of the country, there was no voting at all, because snow prevented helicopters from delivering ballot papers.
New parliamentary elections are to be held later in the year.
Correspondents say interim president Nino Burjanadze is likely to become speaker of parliament, while a third opposition leader, Zurab Zhvania, is a front-runner for the job of prime minister.