An early strike from Rabbi Matondo set Manchester City on their way to a 2-0 win that eased their fears of Division 1 relegation while adding to Sunderland's.
The 17-year-old midfielder made no mistake from close range at the back post after 11 minutes.
It was 2-0 to the visitors on 28 minutes after a superb strike from Tom Dele-Bashiru came back off the crossbar and Ian Poveda netted the rebound.
Sunderland fought back in the second half, but nearly fell further behind when Javairo Dilrosun hit the woodwork.
City climb to eighth with 20 points, four points off Sunderland, who are a point off safety after Tottenham Hotspur's draw with Swansea City the same evening.
See: Sunderland report | Man City report
Next fixtures
Sunderland: 23 Feb v Hull City (H) PL Cup
Man City: 2 Mar v West Ham (H) PL2