LOS ANGELES -- Dwight Howard flashed a wide smile across his face before the Philadelphia 76ers faced the Los Angeles Lakers on Thursday night, receiving his 2020 championship ring with fellow former Laker Danny Green.

It didn't take long for Howard's expression to change from cheer to chagrin.

Howard, making his return to Staples Center, was ejected between the first and second quarters, as referee Kane Fitzgerald called a technical foul on Howard for intentionally walking into Lakers big man Montrezl Harrell on his way to Philadelphia's bench after the buzzer sounded.

Howard and Harrell had already been called for double technical fouls for getting tangled up with 1 minute, 8 seconds remaining in the first quarter, making the second technical an automatic disqualification for Howard.

Harrell pushed Howard away from him and continued toward the Lakers' bench, turning to wave goodbye to the three-time Defensive Player of the Year winner while he pleaded his case with Fitzgerald.

The Sixers won 109-101.

"I just thought it was a very selfish play," Philadelphia coach Doc Rivers said of Howard. "You got one tech, you can't get another one. We just have to have better discipline. I get it. I know there's a lot of emotion. But we had one center on our team, and he got thrown out. I was not very happy with that one. I know it's an emotional game. But he's a veteran. We got to have better discipline."

What prompted the pair's bad blood is unclear, but Harrell, last season's Sixth Man of the Year while playing for the LA Clippers, might not have ever joined the Lakers in the offseason had Howard not signed with the Sixers.

At the outset of free agency in November, Howard tweeted, "I'm staying right where I belong. Laker nation I love y'all. Purple and gold never gets old."

In a bizarre turn of events, though, he quickly deleted the tweet and ended up inking a one-year, $2.6 million contract with Philadelphia. Later that day, the Lakers agreed to a two-year, $19 million deal with Harrell.

Harrell, when asked what caused the altercation with Howard, said, "I don't know, honestly. I don't even care to be real with you. I was just playing basketball, man."

He added, "I'm not backing down from nobody, man. I don't take that lightly. I don't take none of that disrespect. You're not gonna push me all around the court and just feel like you're gonna big-boy me and just attack me or whatever. It's not in my blood, it will never be in my blood. I don't care what nobody feels about it, I don't care who don't like me. It is what it is."