Lopez's dunk with 16.8 seconds put the Nets ahead for good, 84-83, and the Sixers were booed off the court.
The Nets won without Vince Carter, who sprained his right ankle in the second half and scored seven points for the Nets.
The Sixers used a 14-0 run late in the third quarter and appeared on the brink of winning for the 11th time in their last 13 games until they went cold from the floor. They couldn't make a basket. Outside. Inside. From the wing, Beyond the arc. All they heard was clank, clank, clank. Then a lot of boos.
Jarvis Hayes and Harris sank consecutive 3-pointers that pulled the Nets to 82-80 with 3:23 left. Thaddeus Young made one of two free throws to give Philadelphia a three-point lead.
Harris and then Lopez both got inside for the big baskets, leaving the Sixers with one last possession to try and tie.
Andre Miller drove down the baseline and had his attempt blocked by Trenton Hassell. The Sixers got the inbounds pass to Royal Ivey and his long-range jumper was swatted away by Harris.
Miller put his hand on his head in disbelief as the crowd of nearly 18,000 booed the Sixers off the court. The Nets snapped a three-game losing streak and won for only the second time in 10 games.
Miller finished with 19 points and Andre Iguodala had 18.
Coach Lawrence Frank said before the game the Nets were playing like they were in a "fog," and needed a few wins to get a good feeling back in the locker room.
This kind of victory might do it as they continue to chase the eighth spot in the East.
The Sixers signs of slumping from the floor in the third quarter when they scored only three baskets - but one of them was Iguodala's 3-pointer that jump-started the 14-0 run. They drove the lane, got fouled and made their baskets, going 6-for-9 from the from the free-throw line during the spurt. Young and Willie Green scored the other two buckets and they built just enough separation that the Nets never got within single digits until late in the fourth.
Notes: Nets forward Bobby Simmons left the game in the first half with a lower abdominal strain and did not return. ... Dalembert couldn't believe he was whistled for a 3-second violation as he lay on the court holding his ankle Friday. "Do you believe that? Do you believe that?" he said. "I'm like, 'you've got to be kidding me."' Dalembert credited time in a hyperbaric chamber for the speedy recovery. He said he bought one about a year ago. .... Carter was hit with a technical foul in the third quarter. ... 76ers F Elton Brand came off the bench for the fifth straight game.
