The son of Turkmenistan's autocrat leader Gurbanguly Berdymukhamedov won a decisive victory in presidential elections, officials said Tuesday, paving the way to hereditary succession in one of the world's most tightly-controlled countries.

Serdar Berdymukhamedov, 40, won the ballot held on Saturday with 73 percent of the vote, the Central Electoral Commission (CEC) said in a statement on its website.

Nine candidates stood in the poll in the isolated country of six million people, but few doubted that Berdymukhamedov's only son Serdar -- who has pledged to continue his father's course -- would take over the country's top job.

Berdymukhamedov senior, who is now Turkmenistan's outgoing president, chair of the cabinet and senate chief, has been the regime's top decision-maker for the last 15 years.

The strongman known as the gas-rich country's "protector" has dominated public life since the country's founding president Saparmurat Niyazov died in 2006 and tolerates no dissent. 

Last month Berdymukhamedov said he would step aside and allow "young leaders" to govern, triggering a snap vote.

CEC officials took their time to announce the results of one of the world's most predictable elections, that saw Berdymukhamedov face off against relatively unknown civil servants and provincial officials.

On Sunday the CEC's chairman Gulmyrat Myradov told journalists who had attended a press-conference in expectation of hearing the results that the results were being delayed due to "the need for a thorough count".

In the end Berdymukhamedov junior's victory margin proved far lower than the 98 and 97 percent routs posted by his 64-year-old father in the hermit state's last two elections.