Revere, Mass. — Nearly four months after an Election Day defeat in Palmer, Mohegan Sun found itself in the winner's circle Tuesday night after referendum voters overwhelmingly backed its plan to develop a $1.3 billion resort casino on land owned by the Suffolk Downs racetrack.

The margin, unofficially, was 7,171 votes to 4,172 votes, or 63 percent to 37 percent. Sixty percent of voters had endorsed an earlier Suffolk Downs project that died when East Boston voters rejected it.

Revere Mayor Daniel Rizzo, Mohegan Sun officials and hundreds of raucous supporters began celebrating the outcome at Suffolk Downs about 20 minutes after the 8 p.m. close of polls.

"Revere said yes to Mohegan Sun," Rizzo shouted from a ballroom podium. "Revere said yes to jobs; Revere said yes to tax relief ... to better schools and safer streets."

The project, which calls for 4,000 slot machines, 100 table games, poker tables, two hotels, a 10,000-square-foot spa, a 950-seat ballroom and 38,000 feet of meeting space, would be built adjacent to the thoroughbred racetrack but be entirely in Revere. The earlier Suffolk Downs proposal would have straddled Revere and East Boston.

"This is the best second chance ever," Mitchell Etess, chief executive officer of the Mohegan Tribal Gaming Authority, told the crowd. "What a journey this has been."

In November, Mohegan Sun lost the Palmer referendum by 94 votes.

On Tuesday, it needed a win to stay in the running for the one Greater Boston casino license the Massachusetts Gaming Commission is expected to award by the end of June. The one other candidate for the license is Wynn Resorts, which has proposed a project in Everett, a city contiguous to Revere.

"We're going to win this thing," Etess said. "We've got the best location, the best access. ... We're near the highways, Logan Airport, the 'T' — come on."

Referring to the Wynn Resorts proposal, though not by name, Etess said Mohegan Sun could have its project "up to speed and running" quicker than its competitor for the casino license and would seek no concessions from gaming regulators.

"We ask only for the opportunity and nothing more," he said. "We're ready to go."

Mohegan Sun has said its Revere project would create 2,500 temporary construction jobs and 4,000 permanent jobs once it's built. Under its "host community agreement" with the city, it would make up to $33 million in upfront payments to the city before the casino opened and provide annual payment of at least $25 million in the first three years of operation. The minimum annual payments would climb to $28 million in years four through six and to $30 million in the seventh year and thereafter.

The deal also calls for Mohegan Sun to invest an additional $45 million in road and other infrastructure improvements.

Suffolk Downs officials had committed to keeping the racetrack running for at least 15 years if Mohegan Sun is granted the casino license.

b.hallenbeck@theday.com