James finished with 41 points, 16 rebounds and 11 assists for his 11th triple-double of the season and the 53rd of his career in a crucial win for the Cavaliers in Cleveland.
Pacers star Paul George led the scoring with 43 points including 19 in the two periods of overtime, adding nine rebounds and nine assists.
But George's high-scoring display was not enough against a Cavaliers side determined not to lose further ground to the Celtics.
The reigning champion Cavs moved to 49-27 with the victory to stay a half-game behind the Celtics who are 50-27.
The Pacers meanwhile fell to 37-40, leaving them in a tie for eighth place with the Miami Heat.
The Chicago Bulls, who won on Sunday, are now one game clear of Indiana and Miami.
Cleveland's win sets the stage perfectly for what promises to be a titanic battle with Boston on Wednesday.
Crucially, all of Cleveland's big guns appear to be hitting form at the right time.
As well as James' 41-point haul, Kyrie Irving scored 23 points on Sunday while Kevin Love added 20 points and grabbed 12 rebounds. J.R. Smith also weighed in with 18 points on six three-pointers.
The Pacers points came via George, C.J Miles (27), Thaddeus Young (19) and Jeff Teague (17).
James's points total saw him draw level with Kareem Abdul-Jabbar on 787 consecutive regular season games with at least 10 points. Michael Jordan holds the all-time record, with 866 consecutive double-digit games.
source: news.abs-cbn.com
