Hoping for one more championship run from their proud and aging stars, Celtics fans across the city hoped, cheered, and then agonized Saturday night as their team fell, 101-88, to the Miami Heat.

Instead of advancing to the Finals, the Celtics saw their season - and possibly the last game with the Big Three of Paul Pierce, Kevin Garnett, and Ray Allen as teammates - come to a crashing end in Florida.

That disappointment extended from the team’s locker room in Miami to its legions of fans in and around Boston who rooted for another improbable win in a season dogged by injuries and inconsistency.

With four minutes left on the clock, about 400 fans at the Cask ‘n Flagon bar near Fenway Park grew increasingly angry as they watched the Celtics fall farther behind after battling the Heat to a draw for three quarters.

Some fans shook their heads in disbelief and disappointment; others shouted curses at the television screens.

‘I’m very proud of the Celtics. They showed a lot of heart. They were really impressive.’

Alex Pisani, 24 Celtics fan from Easton

Some patrons began to leave, but Bill Kalpakoglou, who lives near the tavern, stayed until the end. “I’m pretty bummed,’’ he said. “They put out a hell of an effort except for the last 5 minutes.’’

As the final seconds ticked away, the crowd and Kalpakoglou, 40, began to applaud the Celtics.

“I’m sad, but no one expected us to be here,’’ he said. “It’s bittersweet - more bitter than sweet.’’

At The Four’s, a restaurant and sports bar on Canal Street, some patrons began filing out in the last seconds, unable to continue watching. Others simply stared at the screen in disappointment.

“It was a game where anything could happen,’’ said Marcello Camducci, 32, of Boston. “They played well.’’

While some Celtics fans mumbled regrets as they headed home, others stayed behind in the subdued bar and pondered where the team had gone wrong.

Bob Antozzi and his daughter flew in from Fredericksburg, Va., to watch the game.

“I thought the second half they didn’t play as tenaciously as the first half,’’ he said. “At the end, they couldn’t catch up. It’s very demoralizing.’’

Some fans were surprised the Celtics were unable to hold a lead.

“It was close the whole game, and in the clutch Miami was the team that came through,’’ said Roger Chiasson, 44, of Boston, sitting at the bar after the game. “With the Celtics’ experience, that’s when you would have thought it would shine.’’

At Jerry Remy’s Sports Bar & Grill in the Fenway, fans continued to chant “Celtics’’ as time expired. But loud curses were heard, too, as other fans quickly finished their drinks and stared at the screen in anger or disbelief.

“I will root with every fiber of my being against LeBron James and the Heat for the next series,’’ said Patrick Shea, 31, of the South End. “There’s nothing likeable about the Heat. I like the [New York] Giants over the Heat.’’

Despite the loss, in which the Celtics led for much of the first three quarters, many fans credited the team for its resiliency, toughness, and passion.

“I think the general consensus is overachievement in the postseason,’’ said Sean Matthews, 31, of South Boston. “We didn’t expect this; this was a great team. It’s the end of an era.’’

Alex Pisani, 24, of Easton, did not want to talk about the loss, but eventually relented. “I’m very proud of the Celtics,’’ he said. “They showed a lot of heart. They were really impressive.’’

When asked if he would root for the Oklahoma City Thunder in the Finals, Pisani reluctantly responded, “I guess.’’

Then he shook his head. “It’s all about the Celtics,’’ Pisani said. “In the end, it’s all about the Celtics.’’

That feeling was evident across Boston before the game, as fans turned out in big numbers at sports bars to cheer the underdog Celtics.

By halftime, they were not disappointed as the Celtics raced to a 53-46 lead.

In the end, optimism was not enough to propel the Celtics to an 18th championship.

Joan Casey, 29, of Boston, held her head. “It’s really the end of an era. We should have won. I really thought we would win this,’’ Casey said.

“It was a good season,’’ she added, before correcting herself. “It was a great season.’’