Boos rained down on the 76ers before halftime of LeBron James' first home game - before Philadelphia mounted the biggest comeback of his glittering career to secure victory.

The 41-year-old NBA legend joined the 76ers ahead of the new season, adding more pedigree to a locker room that also includes Jaylen Brown, Tyrese Maxey and Joel Embiid.

Earlier this week, on opening night, Philadelphia spoiled the New York Knicks' celebrations by winning at Madison Square Garden.

But during Thursday night's clash against the Cleveland Cavaliers - James' former team and hometown franchise - Philadelphia fell 27 points down inside the second quarter. 

That prompted some fans inside Xfinity Mobile Arena to boo their team before halftime. At one point, Cleveland's lead was 29 and ESPN analytics gave Philadelphia just a 1.3 percent chance of victory.

But the Sixers refused to cave and turned the game on its head in the second half. After Philadelphia's biggest comeback of the modern era, James and Co won 114-106. 'We're some tough, uh, basketball players,' Maxey said with a laugh. 'Mom's watching!'

The 76ers trailed until deep into the fourth quarter, with Embiid giving the home team their first lead of the night with less than seven minutes remaining.

Maxey led the way with 32 points, while Embiid added 24 and Brown scored 21. James finished the night with 17 points, 10 rebounds and five assists as Philadelphia moved to 2-0.

Earlier on Thursday, the 41-year-old was blasted by Donald Trump after the NBA star was filmed practicing his golf swing during the national anthem on Tuesday night.

Footage of the Philadelphia 76ers star quickly went viral after their victory over the NBA champion New York Knicks on the first day of the new NBA season.

It showed James pretending to swing a golf club at Madison Square Garden as The Star-Spangled Banner was performed before also practicing his free throw technique.

Trump, a vocal critic of James in the past, lashed out at him in an explosive Truth Social post on Thursday.

The President wrote: 'While listening to our National Anthem, LeBron James disrespects our Country! I said right from the beginning that he’s no good, a TOTAL DISGRACE.

'LeBron James should apologize to all of those Great American Warriors and Heroes who died for the American Flag, and all that our Country stands for!'