Goals either side of half-time from Jobe Bellingham, brother of Real Madrid star Jude, and Wilson Isidor made it four home wins from four matches for the Black Cats.
"It's another win at home. I would like to be more dominant in possession because we have the quality to do that, so we will work on it," said Sunderland boss Regis Le Bris.
West Brom, who began the evening at the summit, went down 1-0 at home to Middlesbrough thanks to Hayden Hackney's 73rd-minute strike.
Blackburn's unbeaten start to the season was ended by a 3-0 defeat at Coventry.
Jake Bidwell and Haji Wright put the Sky Blues in control and Brandon Thomas-Asante secured the three points when he fired home from the edge of the area with six minutes left.
Scott Parker got the better of former England team-mate Wayne Rooney as Burnley beat Plymouth 1-0 to climb to second, courtesy of Josh Brownhill's first-half penalty.
Largie Ramazani's equaliser on the hour earned Daniel Farke's Leeds a point from their trip to his old club Norwich.
Josh Sargent put the Canaries ahead with a 13th-minute penalty after he was brought down by Joe Rodon.
At the bottom, Cardiff finally broke their win duck by beating Millwall 1-0.
Oxford came from two goals down to earn a 2-2 draw at Luton. Hull moved up to ninth with a 3-1 win at QPR.
