Jayson Tatum delivered a magnificent performance in Game 5 of the NBA Finals with 31 points, eight rebounds and 11 assists, and the Boston Celtics capped a dominant season by cruising to a 106-88 victory over the Dallas Mavericks on Monday to capture their first league championship since 2008.

Returning home off a 38-point Game 4 loss that extended the series, the Celtics bounced back with authority by leading the clincher from start-to-finish to put the finishing touches on an unquestionably title-worthy 2023-24 campaign.

After recording the league's best regular-season record at 64-18, Boston went 16-3 in the post-season to earn the 18th NBA title in franchise history, breaking a tie with the Lakers for the most by any team.

Jaylen Brown compiled 21 points, eight rebounds and six assists in Game 5 and was named Finals MVP. The All-Star forward averaged 20.8 points, 5.4 rebounds and five assists per game for the series in addition to playing lock-down defence on Mavericks star Kyrie Irving, who was held under 39 per cent shooting in three of Dallas' four losses.