© AFP / Arif AliTehreek-e-Labaik Pakistan (TLP) party supporters at a rally demanding Bibi's death.
The court, in a three-member bench led by chief justice Saqib Nisar, released the verdict on Wednesday morning in Islamabad, three weeks after they had reached a decision.
The delay followed threats by blasphemy campaigners to hold large protests and kill the judges if they did not uphold the death sentence. Members of the Tehreek-e-Labbaik (TLP), a new political party dedicated to punishing blasphemy, blocked roads in Lahore and pelted police with stones after the ruling.
"Her conviction is set aside and she is to be relieved forthwith if not required in other charges," said Nisar, reading out the judgment.
"It is ironical that in the Arabic language the appellant's name Asia means 'sinful'," reads the judgment written by Justice Asif Khosa, "but in the circumstances of the present case she appears to be a person, in the words of Shakespeare's King Lear, 'more sinned against than sinning'."
The Christian farm labourer, a 47-year-old mother of four, was sentenced to hang for blasphemy in 2010. She had angered fellow Muslim farm workers by taking a sip of water from a cup she had fetched for them on a hot day. When they demanded she convert to Islam, she refused, prompting a mob to later allege that she had insulted the prophet Mohammed.
Bibi remains in Adiala jail, in Rawalpindi, but will be freed as soon as jail officials receive the court order.
On Wednesday, the judges noted that no solid evidence of wrongdoing by Bibi was presented before the court. The three witnesses who did appear, according to observers, presented contradictory stories from the stand.
The two sisters who accused Bibi "had no regard for the truth" reads Khosa's judgment, "and they were capable of deposing falsely", adding that "the said semi-literate young sisters had a reason to level allegations against the appellant which could be untrue."
The judgement goes on to say that the prosecution's evidence from the public gathering, where Bibi was alleged to have insulted the prophet, "was nothing short of concoction incarnate".
The media has been prevented from discussing the case since the verdict was reserved on 8 October.
Paramilitary security forces have deployed across the capital in the past 24 hours, protecting the Judges Enclave and the diplomatic zone. About 300 police have been stationed to guard the supreme court.
On 13 October, Khadim Rizvi, the TLP leader, announced he would "paralyse the country within hours" if Bibi was freed.
On Wednesday morning protests were already growing across the country. TLP workers have descended outside the Punjab assembly in Lahore, while others have gathered to block roads in Karachi. More have returned to the Faizabad interchange in Islamabad, the site of a three-week long protest camp held by the party last year that crippled the capital.
The TLP chief, Afzal Qadri, said that all three judges are now liable for death.
Comment: More on the threats:
"The patron in chief of TLP, Muhammad Afzal Qadri, has issued the edict that says the chief justice and all those who ordered the release of Asia deserve death," party spokesman Ejaz Ashraf said, as cited by the
The Tehreek-e-Labaik (TLP) party called for the death of the chief justice and two other judges in Pakistan's highest court after they spared the life of Asia Bibi, 47, who was convicted of blasphemy in 2010.
The party also demanded Prime Minister Imran Khan's government be ousted following the court's order.
The accusation against Bibi carries an automatic death penalty in Pakistan's legal system, and although the state has never executed anyone for the offence, vigilante mobs often turn murderous.
Bibi, who is the first woman to be sentenced to death for blasphemy in Pakistan, has remained in solitary confinement for the past eight years. The supreme court was due to hear Bibi's appeal in 2016, but delayed the trial after one of the judges recused himself. Ahead of the verdict, the third witness in the trial, a cleric, told the BBC that "reversing the two previous decisions in the case [is] encouraging people to take the law into their own hands".
A journalist who visited her in prison before the verdict said she appeared to have memory loss and confusion.
However, on 7 October, Ashiq Masih, Bibi's husband, said his wife was "spiritually strong" and "ready and willing to die for Christ", adding that she will "never convert to Islam".
In February, Pope Francis met Ashiq at the Vatican, and Christian churches in Lahore held fasts and prayer sessions before the verdict.
The case highlights two issues with blasphemy laws in Pakistan: how allegations can be used to settle personal scores, and lower-court judges feeling unable to acquit defendants for fear of their lives.
The governor of Punjab province, Salmaan Taseer, and the minorities minister, Shahbaz Batti, were murdered in 2011 after they spoke in defence of Bibi and called for reform of blasphemy laws.
Before the verdict, Bibi's lawyer told AP: "I have lost my health. I am a high blood pressure patient, my privacy is totally lost. You have to be in hiding."
Lawyers, who did not want to speak on the record, noted that although the supreme court had at last taken a stand, the after-effect of the trial would serve to encourage lower courts to pass the weakest cases of blasphemy up to the apex court.
Esteemed former senator Farhatullah Babar greeted the verdict, saying the "honourable judges have lit a candle in darkness and raised hopes in hopelessness".
Shahbaz Taseer, son of the murdered governor Salmaan Taseer, told the Guardian: "This is a huge victory for my father, for Pakistan, for the poor, for the judicial system, for every marginalised person in this country.
"I have seen so much in my very short life I have never seen anything like this. I was released [from five years in Taliban captivity], the same day that Mumtaz Qadri [the killer of his father] was hung. But this is even better than that, this is justice at last."
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