A right calf strain in the first round of the Playoffs against the Miami Heat held Porzingis out of the series against the Cleveland Cavaliers and the Indiana Pacers, which the Celtics won 4-1 and 4-0, respectively, but his impact the regular season’s best team was evident and immediate in front of a frantic home crowd.

The Celtics came in as favourites after securing the best regular season record and holding a clear advantage in the history books, as they are the club with the most NBA Finals appearances ever and have claimed 11 titles in the last 50 years, coming out of the Eastern Conference.

Boston, currently tied at 16 titles apiece with the Los Angeles Lakers, hopes to finally top its longtime rival from the West Coast by beating Dallas, but it’s been a good 16 years since their fans had a chance to celebrate and showcase their legendary ‘Celtic Pride’, while other city teams like the Red Sox, Patriots and Bruins have won in baseball, American football and ice hockey, respectively.

The Mavs step back in the Finals after 13 seasons out and have endeared themselves to global spectators with quite the Cinderella story thanks to Slovenian superstar Luka Doncic. The last time a fifth-seeded team lifted the Larry O’Brien trophy was 1995 with the Houston Rockets. That 2006 title team was full of veterans and led by another prized European, Dirk Nowitzki.

The Mavs’ unquestioned leader, Doncic averaged more than 28 points, 9 rebounds and 8 assists per game in the postseason and did manage to score 30 points and grab 10 rebounds, but his sidekick, Kyrie Irving only converted six shots in19 attempts and was limited to 12 points. It was abitter return for the ex-Celtic, as Boston fans booed him heartily and his record against his former team fell to 11 straight losses since he left the franchise for New Jersey.  “It’s not the first time I’ve lost in Boston. I don’t want to continue to make it a habit,” Irving said. “They have had my number a little bit.”

Porzingis, himself a former Mavericks player who didn’t get along with Doncic when they both played in Dallas, had a much better outing against the team that once traded for him. A key contributor for Boston all season, both offensively and defensively, despite being often injured in past years, he came back just in the nick of time to anchor the Celtic’s young stars, much like Bill Walton did for Boston four decades ago. "I did everything I could to prepare mentally for this moment coming back and it paid off, and we got the job done tonight and had a good game," Porzingis said. Walton, who died 27 May at 71, was honoured before the game.

Despite a 29-point deficit in the first half by allowing seven three-pointers in the first quarter alone to the home team, the Mavericks managed to slice the deficit to eight points in the third quarter, only for the Celtics to pull away again with a strong defensive effort, especially on Irving. Boston finished with 16 three-pointers for the night on a whopping 42 attempts, while forward Jaylen Brown scored 22 points to lead six Celtics players who scored in double figures. "Defensively we made some big-time plays," Brown said. "When they cut it to eight, that's when the game started. I liked how our team responded. We stayed composed. Offensively, we got to our spacing and was able to push that lead back out and make some plays on offense. That was a big third quarter." Teammate Jayson Tatum contributed 16 points, 11 rebounds and five assists.

Boston’s great run in the regular season has kept on rolling in the Playoffs, where they have posted a 13-2 record, including Thursday’s win at TD Garden, and have yet to lose away from home. The odds for them look good right now, yet the underdog Mavericks have proved themselves feisty visitors by overcoming home-field disadvantage in their previous three series.

"I think in those moments we were playing our basketball," Doncic said, referring to the third quarter. "We were getting stops. We didn't allow them to offensive rebound. We were having fun out there those couple moments, and that's what we've got to do more."

Boston hosts game two on Sunday, before heading to Dallas for games 3 and 4 next week. "First to four, we've got to focus on the next game," Doncic, who is set to play in the Paris 2024 Olympics, said. "We have to take those threes away. That's what hurt us the most."