Russian opposition leader Alexei Navalny demanded a recount Monday in Moscow's mayoral election after official results showed that the Kremlin-backed incumbent barely escaped facing a runoff with him.

The Moscow Election Commission said Monday that former Kremlin chief of staff Sergei Sobyanin got just over 51 percent of the vote while Navalny garnered 27 percent in second place, a strong result for a Russian opposition leader.

"We don't recognize the results that have been announced. They are rigged," Navalny wrote on his blog, demanding a recount.

If Sobyanin, 55, had won less than 50 percent, he would have faced a runoff with the charismatic 37-year-old Navalny.

The election was closely watched around the world amid concerns over the democratic process in Russia and following Navalny's recent conviction of embezzlement, a charge he says was politically motivated.

Navalny has risen to wide prominence in Russia in the past few years with his anti-corruption campaign.

His frustrated supporters were gearing up for a protest rally Monday evening but Navalny said he was not seeking to bring unrest to Moscow. Instead, Navalny invited Sobyanin, his team and representatives of the election monitoring groups to join in talks.

Sobyanin, who has been mayor since 2010, said in comments carried by Russia news agencies that Moscow had "passed the test for free and fair elections."

Golos, Russia's leading independent election monitor, said the voting appeared to have gone smoothly. It will present its assessment of the vote later Monday.

However, aggregated data collected by election observers throughout Moscow and published on Golos' website showed Sobyanin winning only 49.5 percent of the vote.

Sunday's mayoral election was the first since 2003 and included six candidates. Last year, the Kremlin reversed Putin's 2004 decree abolishing direct elections for the Moscow mayor and other regional leaders.

Prior to the vote, there were fears that election officials would artificially increase the turnout to allow them to add votes for Sobyanin.