They included 13 lawmakers representing Sarkisian's Republican Party of Armenia (HHK).
Thirteen members of Sargsyan's ruling Republican Party - which still holds a majority in parliament - voted for Pashinyan, just barely more than needed to push him over the threshold.
Today, Acting Prime Minister Karen Karapetyan applied to President of the Republic of Armenia Armen Sarkissian with the request to terminate his duties as Acting First Deputy Prime Minister of the Republic of Armenia.
The head of the ruling Republican Party's parliamentary faction, Vagram Bagdasaryan, said his party backed Pashinyan to "ensure stability" in the country.
Former Prime Minister Serzh Sargsyan was forced to resign in April in response to a series of protests triggered by his appointment as prime minister, after he had already served as president for a decade.
Analyst Vigen Akopyan said snap elections looked certain.
A year later Pashinian was elected to the National Assembly on the ticket of Ter-Petrosian's Armenian National Congress (HAK).
Armenian-American rock star and political activist Serj Tankian joined a pro-opposition rally in the Armenian capital, Yerevan, on May 7, appearing on stage alongside opposition leader Nikol Pashinyan before leading the crowd in song. "This process should continue, in line with the wishes of the Armenian people", Jagland said.
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Sibanye's James Wellsted says this is the third tremor in the same area since Thursday. He said the two miners still trapped are "probably dead as well".
Nikol Pashinyan promises to end corruption and election-rigging.
Both Azerbaijan and Turkey have closed their borders with Armenia over the conflict, inhibiting trade and leaving Armenia in semi-isolation. The following day, he was freed and Mr Sargsyan resigned as prime minister, six days after he had been elected.
Pashinian went into hiding following the deadly suppression on March 1-2, 2008 of post-election protests in Yerevan.
In a statement issued Tuesday, Russian President Vladimir Putin congratulated Pashinyan on his victory.
Pashinian declined to shed light on the composition of his cabinet when he spoke to reporters moments after being elected prime minister.
Pashinian, is a former journalist who edited Armenia's best-selling daily newspaper, "Haykakan Zhamanak", from 1999-2012.
Thousands took to the streets in protest, driving Sargsyan to step down 11 days later.
Pending fresh elections "Pashinyan must manoeuvre between the will of the people and the parliamentary ruling party that he does not belong to and which can not begin supporting him", he said.