Premier League champion United had been facing their first Old Trafford loss to Sunderland in 41 years until the brother of United defender Rio Ferdinand deflected Patrice Evra's off-target strike into the net.
Sunderland had been reduced to 10 men in the 85th minute when former United player Kieran Richardson was shown a second yellow card for kicking the ball away in frustration after referee Alan Wiley had blown for a free kick.
The visitors led inside seven minutes through Darren Bent's low strike, but United striker Dimitar Berbatov equalized early in the second half with a perfectly executed scissor kick.
Kenwyne Jones headed Sunderland back in front in the 58th when goalkeeper Ben Foster failed to deal with a high ball into the box.
"We didn't come to sit back at Old Trafford," Jones said. "As you can see they always have a tendency to come back."
Portsmouth's 1-0 victory over Wolves snapped a run of seven straight league losses and will help to lift the gloom at the club, whose players' wages went unpaid this week and whose owner was hospitalized for a kidney stone operation at a time when the club is deperately trying to secure funding.
After on-loan midfielder Hassan Yebda's header clinched the win, manager Paul Hart said owner Sulaiman al-Fahim will be paying the players on Monday and said "new investment" is expected in the coming days.
While the south-coast team's players will now also hope to receive win bonuses, they remain in last place, a point behind West Ham, which has played two games less.
"It's fantastic - we've waited a long time for it," Hart said. "We have shown great courage in difficult situations and we stuck in today.
"Tottenham at the same time (after eight games) last year had just two points, so we are one better than they were. We know we have our work cut out to rise up the table."
Tottenham, which has recovered this season to the extent that the team is in the top four, came from behind twice at Bolton on Saturday to earn a 2-2 draw.
Ricardo Gardner put Bolton ahead after goalkeeper Carlo Cudicini parried Lee Chung-Yong's shot. Spurs equalized in the 34th minute against the run of play when Croatia midfielder Niko Kranjcar slotted home after Peter Crouch's knockdown to score his first goal since moving from Portsmouth.
Kevin Davies restored Bolton's lead in the 69th by meeting Tamir Cohen's cross at the back post with a header.
But the lead lasted less than four minutes with Vedran Corluka meeting Kranjcar's corner to claim a point for Spurs.
Despite Wigan inflicting Chelsea's first loss of the season last weekend, Roberto Martinez's side lost 2-1 at lowly Hull.
Jan Vennegoor of Hesselink and Geovanni scored in an eight-minute spell in the second half and Hull held on to secure its first league victory in six weeks despite Scott Sinclair's late header for Wigan.
"We can breathe a little easier tonight," Hull manager Phil Brown said. "It was important to get ourselves out of the bottom three."
Burnley beat Birmingham 2-1 to stay unbeaten at Turf Moor since being promoted.
Steven Fletcher put Burnley ahead in the 53rd with a left-footed shot that deflected off Joe Hart's legs and into the roof of the net.
Andre Bikey created and scored the second in the 62nd, charging forward and exchanging passes with David Nugent before shooting beyond Hart and into the far corner.
Sebastian Larsson curled in a consolation free kick in the fourth minute of injury time.