Irving scored 11 points in the final 2:33 on four layups and three free throws to give Cleveland back-to-back wins at home for the first time this season and send Boston to its season-high fourth straight loss.
Irving shot 16 for 24 -- setting a career high for field goals made -- and fell one point short of his career-best scoring total, set at New York on Dec. 15.
Tristan Thompson added 21 points for the Cavaliers.
Rajon Rondo led Boston with 17 points while Kevin Garnett scored 16. Paul Pierce, who scored 40 points in a 103-91 win over the Cavaliers in Boston on Dec. 19, finished with 12 points on 3-for-15 shooting.
Irving's layup gave Cleveland an 84-83 lead with 2:33 remaining. He followed with another layup after Rajon Rondo's turnover to put the Cavs up three. Four free throws by Garnett sandwiched around a basket by Alonzo Gee left Cleveland with an 88-87 lead.
After Garnett missed a baseline jumper, Irving dribbled past midcourt and drove to the basket for a three-point lead with 52 seconds remaining.
After Pierce shot an airball, Irving made two more free throws with 18.2 seconds left to put the game away.
The Celtics have dropped four in a row since winning six straight. Rivers blasted his team following Sunday's 103-88 loss in Detroit, a game which Boston never led. The latest loss dropped Boston to 20-21.
"I believe we should be better than that -- and we're not -- so it's hard," Rivers said before Tuesday's game.
[to top of second column]
The Cavaliers acquired three players and a future first-round draft pick from Memphis earlier in the day. Cleveland picked up forward Marreese Speights and guards Wayne Ellington and Josh Selby in exchange for forward Jon Leuer. Speights will help replace Anderson Varejao, who will miss the remainder of the season after developing a blood clot in his right lung. Varejao had had surgery on Jan. 10 to repair a split leg muscle. He was expected to miss two months, but the blood clot was discovered last week and he has been placed on blood thinners.
Irving, who was 7 of 20 from the field in Saturday's loss to Utah, had a strong start against Boston with 19 points in the first quarter, hitting 8 of 10 from the field.
Cleveland led 54-53 at halftime, but two 3-pointers by Avery Bradley and another by Jeff Green helped Boston take a 70-63 lead. The Cavaliers scored the next seven points, but Courtney Lee's 3-pointer as the third quarter expired put the Celtics ahead 73-70.
Cavaliers starting guard C.J. Miles didn't play because of an illness that has hit several players and a couple of assistant coaches.
Sullinger, who played at Ohio State, scored 12 points and had 10 rebounds for Boston.
The Cavaliers' new players were expected to arrive in Cleveland on Tuesday night. They must first pass physicals, and Scott hopes they will be able to practice Thursday and possibly play Friday against Milwaukee.
NOTES: Bradley, who scored seven points, continues to play with sore ribs. "I feel for Avery because that's a hard injury to play through," Rivers said. "It hurts to breathe and it hurts every time you get hit anywhere near your ribs." Scott has traded text messages with Varejao, who remains hospitalized in the Cleveland Clinic. ... The Cavaliers waived G Jeremy Pargo and recalled C Kevin Jones from Canton of the Developmental League.
Copyright 2013 The Associated
Press. All rights reserved. This material may not be published,
broadcast, rewritten or redistributed.