James Harden felt "carelessness" on rebounds proved costly for the Brooklyn Nets as they were beaten by the Philadelphia 76ers on Thursday.

Despite the return from COVID-19 protocols of Kevin Durant, who put up 33 points, the Eastern Conference Leaders lost 110-102 at Barclays Center.

The Nets responded to falling behind in a high-scoring first quarter to lead by seven points in the third, Harden assisting Durant for two three-point jumpers in the space of 23 seconds.

However, Philadelphia mounted a late comeback before easing to a win that saw them improve to 19-16 for the season.

Harden tied Durant as top scorer for the Nets as he recorded a triple-double of 33 points, 14 rebounds and 10 assists. It was his sixth of the season, a tally surpassed only by the Los Angeles Lakers' Russell Westbrook (eight).

Still, he was frustrated that they let their third-quarter lead slip by giving up too many opportunities.

"They've got more than enough talent to have a really good game after a really good first quarter," he said.

"We climbed back into the game, did a really good job locking down defensively and just doing what we were supposed to do. Obviously, 16 points in that second quarter, we got a chance in that third quarter, went up by eight or something, but we allowed them to get offensive rebounds and more shots in general.

"The rebounds were] a little bit of carelessness, a little bit of decision-making. I had a couple I wish I could have got back. That's the game right there. You talk about it in training camp, not allowing the opposing team to get so many more shots than us. Tonight was a case of that."

Next up for the Nets is a home game with the Memphis Grizzlies on Monday before they head to the Indiana Pacers next Wednesday, when Kryie Irving could make his first appearance of the season.

Irving, who was back on the practice court this week, is unvaccinated against COVID-19 and so is only able to play in road games due to New York City regulations.

Harden said of his team-mate: "He looked like Kyrie: elite. The same Kyrie. We're happy to have him back and we've got to get him on the court."