Aliyev secured a widely-predicted landslide in the tightly-controlled ex-Soviet state with almost 85 per cent of the vote, with main opposition challenger Jamil Hasanli in distant second place, partial results showed.
Over 1,000 supporters of the president started partying ahead of the announcement of the official results, cheering and dancing at a celebratory pop concert in central Baku.
"We can say that Ilham Aliyev has been elected president for another five years," said Ali Ahmedov, executive secretary of Aliyev's ruling New Azerbaijan party.
Aliyev was easily winning the elections with some 84.7 per cent of the vote, the central election commission said, in partial results based on a 36 per cent vote count. Hasanli was in second on less than five percent of the vote
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The 51-year-old Aliyev came to power in a disputed 2003 vote after the death of his powerful father Heydar, a former KGB officer and Communist-era boss who ruled the ex-Soviet nation of 9.5 million people for the preceding 10 years.
Aliyev, who has a vice-like grip over most media in the country, has stayed away from televised debates and passed up public rallies ahead of the polls.
An initial exit poll from the officially-accredited Prognos agency put Aliyev on almost 84 per cent of the vote, far ahead of Hasanli, in second place with around eight percent.
Some 72 per cent of Azerbaijan's roughly five million registered voters cast their ballots, the central electoral commission said.