At 8 p.m., just as the polls close, crowds started to trickle into the ballroom at the Boston Park Plaza hotel, union banners hanging from the balconies.

Walsh supporters clustered in groups of two and three around television screens to watch the election returns.

Early in the night, Connolly had the lead. But Serjo Melovich — a campaign volunteer and member of the hotel workers union, seemed unfazed.

"We are heavily convinced he will win," he said. "That's why we are here."

Melovich said he worked feverishly to get out the vote for Walsh. He spent 10 hours in the field, canvassing in Dorchester — Walsh’s home turf.

When the returns showed Walsh and Connolly tied at 50 percent, a loud cheer erupted in the ballroom.

The crowd swelled to about 1,000. I counted more than a few Red Sox jerseys and union t-shirts.

But the room also reflected the diverse coalition that Walsh had to cobble together in order to win.

Walsh waited until 10:45 to make his victory speech. He said he was waiting for a call from President Barack Obama.

The mayor elect looked a little dazed as he wove his way through the throngs on stage to the center podium.

"You know, let me tell you, my parents had big dreams for their kids, but I'm not sure it was this big," Walsh said. "I am so grateful and honored for tonight's results. For this kid from Taft Street in Dorchester, you've made Boston a place where dreams come true."

Walsh promised to turn Boston into a hub of opportunity, a town where everybody can get ahead, not just a privileged few.

"This is Boston Strong," Walsh said. "And together, we're going to make Boston even stronger. We're going to do it by expanding opportunities, building communities, and ensuring equality for all."

Walsh thanked his family, his supporters in the labor movement, his opponent, John Connolly, for his leadership on education. And his predecessor Mayor Tom Menino for bringing Boston successfully into the 21st century.

"Mayor Menino's legacy is a world-class city that's attracting new people, a vibrant economy, a strong fiscal position," he said.

Walsh said in the coming days he will release the details of a transition plan. Cannons spew confetti into the air, and Walsh assures Boston the best is yet to come.