Hawes set a season high for points and also had seven assists while helping the Sixers snap a five-game losing streak. Thaddeus Young had 16 points and 10 rebounds.
Evan Turner also scored 16 points and Dorell Wright had 10. 76ers coach Doug Collins won his 100th game with the team.
Deron Williams had 27 points and 13 assists for the Nets, who had won three in a row.
Philadelphia grabbed control in the second quarter and never trailed in the second half. It was a rare feel-good win for a team that had high expectations before center Andrew Bynum was lost indefinitely with knee injuries.
With the Sixers up big, Williams tried to rally the Nets on his own, and for a while it worked. He converted a three-point play and then sank two more from the free-throw line to get Brooklyn within eight in the fourth.
But Williams also threw the ball away on a baseline drive, and later missed an open look with the Nets down eight. The Nets missed seven of their next eight shots until Joe Johnson hit a 3 with 1:25 left to make it 101-95.
Philadelphia still managed to hold on for its second win in the last 14 games, taking advantage of some time at home following a winless three-game road trip. The Sixers haven't won a road game (0-13) since beating the Los Angeles Lakers on Jan. 1 and are 6-23 overall.
The Sixers continue their four-game homestand on Wednesday night against the streaking Miami Heat. After games against Indiana and Portland, the Sixers play 12 of their final 16 games on the road. That could be a stretch that not only keeps the Sixers in the draft lottery, but has them in the mix for a top-10 pick.
The Nets entered only 2½ games behind New York for first place in the Atlantic Division. But they made only 11 of 16 free throws and shot 31 percent (6 of 19) from 3-point range while never mounting a serious charge at the Sixers. Johnson scored 20 points and Brook Lopez had 19.
Damien Wilkins, who scored 13, helped the Sixers build on their halftime lead with a pair of 3-pointers in the third that stretched the lead to 14. Wilkins hit his second 3, then blocked Lopez on the other end. The block was his eighth of the year and he talked a little trash in celebration.
Hawes, the much-maligned 7-foot center, buried a jumper then turned a nice dish in the lane from Holiday into a one-handed dunk that had the Sixers thinking upset.
The Nets then scored nine of the final 11 points of the quarter to cut into the lead, but it just wasn't enough.
NOTES: New Eagles coach Chip Kelly visited Collins before the game. Collins said he told Kelly, "What an incredible city this is and how much they love their Eagles, the fan base here and stuff. ... I said, he couldn't find a better place to be a coach." ... The 76ers celebrated stat guru Harvey Pollack's 91st birthday. Pollack, who turned 91 on Saturday, got a phone call from NBA commissioner David Stern. Pollack said Stern told him it was "pleasure and an honor" to be his friend. He was a statistician and writer when Wilt Chamberlain scored 100 points. Pollack wrote "100" on a piece of paper and gave it to Chamberlain to hold for the classic black-and-white snapshot.