Deng hit 9-of-15 shots from the field and Anderson Varejao contributed 18 points and 18 rebounds for the Cavs, who have won three of their last four games.
Cleveland sizzled from long range, sinking 13-of-17 shots from beyond the arc compared to 13-for-34 for the Lakers.
Nick Young came off the bench to lead the Lakers with 28 points. Jodie Meeks followed with 26 and Pao Gasol added 20 plus a dozen rebounds. Los Angeles shot 52.4 percent from the field but were out-rebounded 35-27 and lost their fifth in a row.
Cleveland outscored Los Angeles 31-22 in the third quarter and took the lead for good on a 25-foot 3-point shot with 8:11 to play in the fourth. The Lakers pulled to within a bucket late when Deng committed a three-shot foul on Nick Young, who converted all three times to make it 118-116 with 25 seconds to play. Young, however, missed a 3-point try with three seconds to play and Cleveland leading by four.