The Sixers opened the fourth quarter on a 25-6 run to send the Hawks to their second demoralizing loss in two nights. The Bulls won in Atlanta 114-81 on Tuesday night.
Williams and Young, a former Georgia Tech standout, keyed the Sixers' rally off the bench in the fourth. Philadelphia was down 10 late in the third quarter before an 11-0 run early in the fourth fueled the comeback.
Josh Smith had 33 points and 12 rebounds for the slumping Hawks. Smith's 3-pointer with 1.6 seconds left pulled the Hawks within three.
Iguodala hit two free throws to clinch the win.
HEAT 100, PISTONS 94
In Auburn Hills, Mich., Dwyane Wade scored 24 points and former Georgia Tech star Chris Bosh added 23 to help Miami rally.
LeBron James had 19 points, eight rebounds and seven assists for Miami, which has won six of seven.
The Heat trailed by 11 late in the third quarter before Mike Miller made a 3-pointer in the final seconds. Miami then scored the first 15 points of the fourth to take an 88-81 lead.
GRIZZLIES 90, CELTICS 87
In Boston, Marc Gasol scored 11 points with 11 rebounds and Zach Randolph had 13 and eight to lead Memphis.
Gasol stole the ball from Ray Allen and then hit a layup with just over a minute left to put Memphis ahead 88-85. After Gasol missed a pair of free throws with 4.6 seconds left and a chance to go up by five, Paul Pierce missed an off-balance 3-pointer that would have sent the game into overtime.
NETS 98, CAVALIERS 94 (OT)
In Cleveland, Kris Humphries grabbed a career-high 23 rebounds and made several big plays in overtime, leading New Jersey to just its fifth road win.
Jordan Farmar's two free throws with 3.8 seconds left helped seal it for the Nets, who snapped a four-game losing streak.
PACERS 111, BOBCATS 88
In Charlotte, N.C., Danny Granger scored 33 points and Indiana created breathing room from one of its closest competitors for the Eastern Conference's final playoff spot.
Tyler Hansbrough added 24 points for the Pacers, who moved three games ahead of Charlotte by completing a four-game season sweep.