Tyrese Haliburton turned a 3-pointer into a tiebreaking, four-point play with 1:33 remaining as part of a triple-double, and the Indiana Pacers outfinished the Boston Celtics for a 122-112 victory in the Eastern Conference semifinals of the NBA's inaugural in-season tournament Monday in Indianapolis.

The result vaults Indiana into the Eastern finals of the event, which will be played Thursday night in Las Vegas. The winner of Tuesday's other Eastern semifinal between the New York Knicks and Milwaukee Bucks will join the Pacers in Las Vegas.

The Celtics will drop back into NBA regular-season action Friday.

After a Jayson Tatum jumper produced the sixth and final tie of the fourth period with 1:57 remaining, Haliburton buried his game-changing shot at the shot-clock buzzer as Jaylen Brown was fouling him. Haliburton's subsequent free throw put the Pacers up 109-105.

Indiana then put the game away by scoring the game's next five points on a Buddy Hield 3-pointer and an Aaron Nesmith dunk, both assisted by Haliburton. Boston, meanwhile, missed three consecutive shots, including 3-point attempts by Tatum and Brown.

The Celtics held the upper hand for much of the first half before the Pacers, the NBA's highest-scoring team, exploded for 37 points in the third period to go up 85-78. Haliburton had 12 of his team-high 26 points in the quarter, including two of Indiana's six 3-pointers.

Boston drew even by Brown's 3-pointer at the 6:07 mark of the fourth quarter.

Overall, Haliburton shot 5-for-11 from 3-point range to account for most of his scoring for Indiana, which connected on 19 treys and outscored the visitors 57-36 from beyond the arc.

The star guard also found time for a game-high 13 assists and a team-high-tying 10 rebounds for his first career triple-double.

Myles Turner compiled 17 points and 10 rebounds for the Pacers, who earned the home court in the Eastern semifinals by virtue of having gone 4-0 in group play. Hield finished with 21 points, while Bennedict Mathurin had 16, Nesmith 14, Bruce Brown 13 and Obi Toppin 12.

The Celtics, who had walloped the Pacers 155-104 at home on Nov. 1 and came into the Monday contest on a three-game winning streak, were led by Tatum with a game-high 32 points and Brown with 30. Tatum completed a double-double with a game-high 12 rebounds.

Derrick White had 18 points and a team-high eight assists for Boston, which was missing injured Kristaps Porzingis (calf). Sam Hauser came off the bench for 15 points.

--Field Level Media