James Harden called the "perfect game" according to Philadelphia 76ers head coach Doc Rivers after leading them to a 121-102 win over the Brooklyn Nets in Game 1 of their playoffs first round series.

Harden starred against his former franchise, scoring 23 points on seven-of-13 three-point shooting with 13 assists.

The Nets put attention into MVP candidate Joel Embiid throughout, restricting him to 26 points, but the 76ers stepped up elsewhere, making a franchise-record 21 three-pointers in a playoff game.

"James, I thought that was one of his best games as a 'catcher' where he was calling the perfect game," Rivers told reporters about Harden.

"He's in shape, he's healthy. He's confident in how we play. Last year, even when he was playing, he was like 'am I doing the right thing here?'. There was a lot of good there."

Rivers pointed out that the 76ers also generated 19 more shots than the Nets (89-70), while Harden acknowledged the Nets' tactics to limit Embiid's tactics but hailed his side's shooting, going at 48.8 per cent from beyond the arc. Fifteen of the 76ers' 21 triples were uncontested.

"I mean, he's the MVP," Harden said of Embiid. "So it's like, would you rather him score 40, or live with us making shots? Either way, it's fine. We'll be ready either way."

Embiid's 26 points came on seven-of-15 field-goal shooting with five rebounds, three assists and two blocks. The MVP contender was full of praise for Harden's impact.

"He's the best playmaker in the league, by far," Embiid said. "But we don't want him settling. I don't want him to fall in love with just that. We need him to be aggressive, and he was today.

"I think that's the key - not just being a playmaker, just being aggressive, going downhill and creating for himself and everyone else."