But despite the Hun Sen’s strong showing in last weekend’s general elections, the one-time Khmer Rouge fighter faces the uncomfortable prospect of trying to form a coalition government.
And with the final ballot results not due until August 8, some fear a repeat of the violence that followed the 1998 election.
With about a fifth of the votes counted, the National Election Committee (NEC) declared Hun Sen's Cambodian People's Party (CPP) well ahead with 52.5 percent of votes.
The opposition Sam Rainsy Party (SRP), run by Hun Sen's arch rival and former finance minister Sam Rainsy, was second with 20.5 percent. The royalist FUNCINPEC, led by Prince Norodom Ranariddh, was third with 18 percent.
It is widely expected that the CPP will not win the two-thirds majority in the 123-seat National Assembly needs to govern alone and will need to seek a coalition partner.
Tough talks lie ahead
Diplomats warned that talks over forming a coalition government would be complex and could last for weeks.
"Both (FUNCINPEC chief Ranariddh and Rainsy have the capacity to block the functioning of institutions, and they are very likely to come up with initiatives for regrouping anti-Hun Sen forces," one envoy told AFP.
"They have diverging interests – but for sure they will make things more complicated," he said.
CPP supporters are celebrating
as the party cruises to victory
Rainsy complained on Monday of fraud and cheating during the polls, widely seen as being the most peaceful and stable in Cambodia's short democratic history.
FUNCINPEC, the junior coalition partner in the outgoing government, also disputed the preliminary results. It said it would wait for the final official results before conceding defeat.
More than 30,000 security forces remain posted across Cambodia - previous elections in this fledgling democracy have been blighted by violence and bloodshed.
Aid hinges on fair poll
With election organisers still furiously counting votes, observer groups delivered broadly positive verdicts on the poll.
Their rulings could open the door for millions of dollars of extra aid to what remains one of Asia's poorest nations. Cambodia's government relies on international donors for some 60 percent of revenue.
"We feel in general the electoral process was quiet and smooth except some violence such as shooting in the air in (the eastern province of) Svay Rieng," said Thun Saray, head of the Committee for Free and Fair Elections in Cambodia, according to Reuters.
The United States said late on Monday it was generally pleased with the electoral process.
The verdict from European Union monitors on Wednesday will be closely watched as the benchmark for overall credibility.