Davis' Family and advocates of 39-year-old Troy Davis have long urged he deserves a new trial as seven of the nine witnesses who helped put him on death row have recanted their testimony. His supporters erupted into cheers and tears when the stay was announced at about 5:20 p.m. EDT.
"This is not over yet," said Davis, who sounded upbeat and optimistic speaking to the crowd by phone. "This is the beginning of my blessing."
Protesters had arrived by the busload to protest the execution, waving signs and wearing blue shirts that proclaimed "I am Troy Davis." The Rev. Al Sharpton, who accompanied the Davis family to the protest, led the crowd in a Gospel hymn after the news was announced.
"One week doesn't seem like a long time," Sharpton said of the decision by the court, which is set to discuss the case Monday. "But if you have two hours to live, it's a lifetime."
Davis' sister, Martina Correia, vowed that her brother's case would effect change in the state. When asked what made the difference in the court's decision, she responded: "The truth."
"We're going to shake the foundation of the death penalty in Georgia," she said tearfully while fielding calls from well-wishers.
Prosecutors have labeled the statements of witnesses who recanted "suspect," and courts had previously refused requests for a new trial.
The stay will remain in effect while the court considers Davis' appeal. Davis wants the high court to order a judge to hear from the witnesses who recanted their testimony and others who say another man confessed to the crime.
Influential advocates, including former President Jimmy Carter and South Africa Archbishop Desmond Tutu, insist that there's enough doubt about his guilt to merit a new trial.
A divided Georgia Supreme Court has twice rejected his request for a new trial, and had rejected his appeal to delay the execution Monday afternoon. The Georgia Board of Pardons and Paroles also turned down his bid for clemency.
Davis was convicted of the murder of 27-year-old officer Mark MacPhail, who was working off-duty as a security guard at a bus station.
MacPhail had rushed to help a homeless man who had been pistol-whipped at a nearby parking lot, and was shot twice when he approached Davis and two other men.
Witnesses identified Davis as the shooter, and at the 1991 trial, prosecutors said he wore a "smirk on his face" as he fired the gun.
But Davis' lawyers say new evidence proves their client was a victim of mistaken identity. Besides those who have recanted their testimony, three others who did not testify have said Sylvester "Red" Coles - who testified against Davis at his trial - confessed to the killing.
Coles refused to talk about the case when contacted by The Associated Press during a 2007 Chatham County court appearance and has no listed phone number.
Prosecutors have contended in court hearings the case is closed. They also say some of the witness affidavits simply repeat what a trial jury has already heard, while others are irrelevant because they come from witnesses who never testified.
More than an hour after the Supreme Court's decision was announced, jubilant supporters were still celebrating in the sprawling parking lot of a gas station across the street.
"We've won one battle, but we still have a long way," said Davis' mother, Virginia.
"This is extremely rare," said Jared Feuer, a regional director of Amnesty International, who said attorneys will urge the Supreme Court to exonerate Davis. "That's the central thrust of this case: Whether or not guilty or innocence matters more than procedure."
Across the parking lot, a half-dozen members of the Fraternal Order of Police who showed up in support of the MacPhail family sat quietly in a van.
"I'm here because that guy killed a police officer," said Freddie Richardson, who retired after 40 years in law enforcement. But he said he wasn't disappointed by the court's decision.
"This happens all the time," he said.
Meanwhile, a man was set to be executed Tuesday in Florida after the U.S. Supreme Court refused to grant him a stay. Richard "Ric Ric" Henyard, 34, was convicted of the 1993 shooting deaths of two sisters - 7-year-old Jamilya Lewis and Jasmine Lewis, 3.
Their mother, Dorothy Lewis, survived after she was raped and shot several times during a carjacking. Both girls, with their mother when they were seized by Henyard and an accomplice, were shot in the head when they cried out for her.