Miami Heat Beat Boston Celtics in Game 7 to Advance to NBA Finals

The N.B.A.’s Eastern Conference championship trophy had found its way to the visiting locker room at TD Garden on Monday night. Set atop a couple of packing trunks with metallic trim, the trophy — a sterling silver replica of a basketball — was an attraction for the Miami Heat, who had earned it the hard way with their stunning 103-84 victory over the Boston Celtics in Game 7 of the conference finals.

Players and staff members, clad in N.B.A. finals hats and T-shirts, positioned themselves next to to the trophy for photographs and selfies, memorializing the team’s beautiful struggle before a late-night flight to Denver, where they will face the Nuggets for the N.B.A. championship starting Thursday.

“We never thought it would be easy,” Miami forward Bam Adebayo said.

The Heat’s resurgence as the East’s No. 8 seed has surprised everyone but them. Even when they were scuffling through the regular season, losing nearly as often as they won, Coach Erik Spoelstra stuck with his approach. Spoelstra said they were capable of improving if they continued to focus on their daily work. There was nothing especially sexy about it — meeting after frustrating losses, watching film, practicing hard.

“I think probably people can relate to this team,” Spoelstra said. “Professional sports is just kind of a reflection sometimes of life, that things don’t always go your way. The inevitable setbacks happen, and it’s how you deal with that collectively. There’s a lot of different ways that it can go: It can sap your spirit. It can take a team down, for whatever reason.

“With this group, it’s steeled us and made us closer and made us tougher.”

They will need that toughness against the top-seeded Nuggets, who secured their first trip to the N.B.A. finals by completing a sweep of the Los Angeles Lakers in the Western Conference finals a week ago. The Heat are just the second eighth seed, after the 1998-99 Knicks, to reach the championship round under the current playoff format.

“Everybody’s confidence is so high,” said Heat forward Jimmy Butler, who was named the most valuable player of the series after scoring 28 points in Game 7. “We have belief that we can do something incredibly special. So we are going to hit the ground running when we get to Denver, and I like our chances.”

The Nuggets, who are rested and deep, figure to be the Heat’s toughest challenge to date. At Butler’s postgame news conference, he was asked how he and his teammates planned to slow Nikola Jokic, the Nuggets’ star center and a two-time M.V.P. Butler said he was giving himself until midnight — it was 11:42 p.m. at the time — before he began to think about the coming series.

“I don’t know,” he said. “I’ve got two days to figure that out.”

At this late stage, though, the Heat appear to savor absurd tests. They traveled a long road just to reach the conference finals. They had to defeat the Chicago Bulls in a play-in game to slip into the postseason. They proceeded to lose two rotation players, Tyler Herro and Victor Oladipo, to injuries in their first-round series with the East’s No. 1 seed, the Milwaukee Bucks.

After Miami won the first three games of its series with Boston, Spoelstra said “a lot of pent-up stuff” had been fueling his team but declined to elaborate. His players were more forthcoming: They recalled being eliminated by the Celtics in the conference finals last season, an especially disappointing exit since the Heat were the East’s top seed and the series went seven games.

This time around, the Heat built a 3-0 series lead — and promptly lost three in a row, a demoralizing stretch that included a brutal, last-second loss in Game 6 when the Celtics’ Derrick White converted a putback layup at the buzzer off an errant 3-pointer. The Heat could have crumbled. Instead, they dipped into their bottomless well of perseverance.

“Sometimes you have to suffer for the things that you want,” Spoelstra said, adding: “Sometimes you have to laugh at the things that make you cry.”

On Monday, before a hostile Boston crowd that was at a fever pitch during player introductions, the Heat seemed intent on drowning out the noise by relying on their defense. The Celtics missed all 10 of their 3-point attempts in the first quarter. The Heat led by as many as 17 points before halftime.

Caleb Martin, a small forward who moved into the starting lineup for Games 6 and 7, was the Heat’s most consistent player of the series. He had 26 points in Game 7 and made of 11 of his 16 shots, including four 3-pointers.

Gabe Vincent, the team’s starting point guard, played the final two games with a sprained ankle. And Duncan Robinson came off the bench to make timely 3-pointers.

“We have some hoopers,” Butler said. “We have some real-deal basketball players that can score, can defend and can pass and can win games for us.”

The Heat’s role players were the difference in a series against the Celtics, who figured to make another deep playoff run after losing to the Golden State Warriors in the N.B.A. finals last season. But obstacles — both predictable and unforeseen — hindered them before they even convened for the preseason.

Atop the list was the sudden absence of Ime Udoka, who, as the Celtics’ first-year head coach last season, left his defense-minded imprint on the team. But in September, less than a week before training camp, the Celtics suspended him for the season for “violations of team policies.”

The entire situation cast an unwelcome shadow on the Celtics as they sought to focus on the season ahead. “It’s been hell,” Marcus Smart, the team’s starting point guard and last season’s defensive player of the year, said at the time.

Instead of going outside the organization to hire an experienced coach as Udoka’s replacement, the team prioritized continuity by temporarily promoting Joe Mazzulla, who had been an assistant on Udoka’s staff.

The Celtics named Mazzulla as their permanent head coach in February and officially severed ties with Udoka, whom the Houston Rockets hired as head coach last month.

But Boston slumped over the final weeks of the regular season, slipping to the No. 2 seed in the East behind Milwaukee, and needed six games to eliminate the Atlanta Hawks in the first round.

The pressure only mounted on Mazzulla — and on the team’s two stars, Jayson Tatum and Jaylen Brown — during the Celtics’ conference semifinal matchup with the Philadelphia 76ers. Tatum and Brown were inconsistent as the series stretched to seven games.

But after Tatum scored 51 points in a series-clinching tour de force against the 76ers, the Celtics ran into the Heat, a savvy and experienced opponent with payback in mind.

The Heat were not about to let up against the Celtics — not after a season of growth under Spoelstra, not with Butler filling his more unsung teammates with confidence, and not against an opponent that had buried Miami’s championship dream a year ago.

“Nobody is satisfied,” Butler said. “We haven’t done anything. We don’t play just to win the Eastern Conference — we play to win the whole thing.”