Celtics forward Jayson Tatum  celebrates during the second half of Boston’s 114-111 win over the Indiana Pacers in Game 3 of the Eastern Conference finals Saturday night in Indianapolis. Tatum finished with 36 points, 10 rebounds and eight assists, helping the Celtics move within one victory of the NBA Finals. Michael Conroy/Associated Press

INDIANAPOLIS — Jrue Holiday overcame an illness to convert the go-ahead three-point play with 38 seconds left, then make the game-saving steal to help the Boston Celtics rally from an 18-point deficit and beat the Indiana Pacers 114-111 on Saturday night for a 3-0 lead in the Eastern Conference finals.

Boston can clinch its second trip to NBA Finals in three seasons with a Game 4 win Monday in Indianapolis.

Jayson Tatum matched his Game 1 total with 36 points and had 10 rebounds and eight assists. Jaylen Brown added 24 points, and Al Horford scored 23 points with seven 3-pointers as the Celtics won their sixth straight playoff game and stayed unbeaten on the road this postseason.

Holiday played despite being listed as questionable because of an illness.

“For him to come out here and put it all on the line for us and come up with a big play to win the game, we’ve got a hell of a team,” Tatum said in his postgame TV interview.

Andrew Nembhard led the Pacers with a career-high 30 points, but Holiday stole the ball from him with 3.3 seconds remaining as Boston protected a one-point lead. T.J. McConnell finished with 23 points, nine rebounds and six assists, while Myles Turner and Pascal Siakam each had 22 points.

Indiana played without All-NBA guard Tyrese Haliburton, who sat out because of a left hamstring injury, and certainly missed him as Boston closed the game on a 13-2 run. It was the first loss in seven postseason home games for the Pacers.

The sellout crowd, decked out primarily in gold checkered flag shirts featuring dozens of individual stamps of Indiana’s state outline as part of the Indianapolis 500 weekend celebration, helped inject energy with Haliburton out.

But the crowd was quieted by Holiday’s big layup, the ensuing free throw, and the defensive play of the game. He closed it out by making two free throws with 1.1 seconds to go.

Indiana had a chance to force overtime, but Aaron Nesmith’s 3-pointer was off the mark.

It was a wild game, with Indiana taking an 18-point lead midway through the second quarter and again midway through the third. But Boston responded the second time by forcing a flurry of turnovers that it turned into a 13-4 spurt to close to within 90-81 after three quarters.

The Celtics were just getting started. Boston opened the fourth quarter on a 9-3 run that cut it to 93-90 on a 3 from Horford with 8:29 to play.

Then, after Indiana rebuilt a 107-99 cushion with 3:05 left, Boston closed the game on the 13-2 run that sealed its fifth consecutive road victory in these playoffs.