LeBron James finished with 30 points, 12 assists and 10 rebounds for his 80th career triple-double but his efforts proved in vain as Kyrie Irving, Marcus Smart and Marcus Morris dealt another blow to the Lakers' play-off hopes.
Irving helped keep the Celtics on track for the post-season with 30 points, seven rebounds and seven assists, while Smart and Morris both finished with 16 points to help guide Boston to their third straight win.
The Lakers – without three starters due to injury – have now lost five in a row.
James: 30 pts, 12 ast, 10 rebWagner: 22 pts, 6 rebWilliams: 18 pts, 10 reb pic.twitter.com/Gv5sL0HjZL
— Los Angeles Lakers (@Lakers) March 10, 2019
In Milwaukee, Giannis Antetokounmpo top-scored with 26 points and added 13 rebounds to lead the Bucks to a 131-114 victory over the Charlotte Hornets.
Brook Lopez added a solid 25 points and grabbed eight rebounds as the Bucks recorded their 50th win of the season – reaching the feat for the first time since 2001.
Meanwhile, the Phoenix Suns' three-game winning run was ended by the Portland Trail Blazers.
CJ McCollum scored 26 points and Damian Lillard added 18 for the home victory.
Minnesota's Karl-Anthony Towns had a night of mixed fortunes, scoring a huge 40 points before leaving the court injured at the end of regulation. The Timberwolves went on to beat the Washington Wizards 135-130 in overtime.
In the night's other games, the Brooklyn Nets scored their third win in a row with a a 114-112 victory over the Atlanta Hawks and the Sacramento Kings overcame the New York Knicks 102-94 on the road.