Toronto (55-21) will finish no worse than second in the Eastern Conference, but their grip on the top spot that has been theirs to lose for the past month-plus has become tenuous after a 110-99 loss at Boston on Saturday cut their lead for that and the Atlantic Division lead to two games with six to play.
DeMar DeRozan had 32 points, seven rebounds and seven assists, but only four of those points came in the fourth quarter as the Raptors were outscored 16-5 in the final 5:26 and have now alternated wins and losses in their last eight games.
The second of those four defeats was a 132-129 loss at Quicken Loans Arena on March 21 in which Toronto scored 79 first-half points and held a 15-point lead at halftime before Cleveland stormed back in the second half behind a monstrous effort from LeBron James, who had 35 points, 17 assists and seven assists without committing a turnover.
The Cavaliers (47-30) continue to fend off the Indiana Pacers for the Central Division lead and the Philadelphia 76ers for the No. 3 seed in the Eastern Conference. James had his worst shooting game of the season against Dallas on Sunday, going five for 21, but still finished with his 17th triple-double of the season as he totaled 16 points, 13 rebounds and 12 assists in a 98-87 victory.
Jordan Clarkson and J. R. Smith combined for 31 points off the bench and Kevin Love had 13 points and 13 rebounds, but it was Cleveland's oft-maligned defense that delivered this win, holding the Mavericks scoreless for a 5:08 stretch of the fourth quarter while the Cavaliers rallied with a 13-0 burst.