Kevin Keegan's side followed their Good Friday triumph at Tottenham with a comfortable win against the already relegated Black Cats, with City far too strong for the visitors who suffered their 12th successive defeat as they look set to record a record low Premiership points total.
Sunderland, cast adrift with only 19 points, still need a further 6 from their three remaining matches to match Watford's total of 25.
City won the match in a two-minute spell late in the opening half when Marc-Vivien Foe and Robbie Fowler both hit their target.
Nicolas Anelka broke down the right and cut the ball back for on-loan Foe to fire home his eighth goal of the season.
Barely had the match restarted then goalkeeper Mart Poom was picking the ball out of the net for a second time.
City captain Ali Benarbia played a delightful throughball for Fowler to lob the keeper from the edge of the penalty area.
It was only Fowler's second goal in ten league matches since his £6,000,000 pound from Leeds.
Sunderland might have been given a lifeline early in the second half when City keeper Peter Schmeichel made a brilliant double save to deny Kevin Phillips and Marcus Stewart.
City should have added to their tally but had to wait until the 80th minute before adding a third when substitute Djamel Belmadi broke down the left and fired a low cross across the face of goal for Foe to side foot his second of the match from six yards.
And with Cameroon international Foe still desperate to complete a permanent move to City, the goals will not have done his prospects any harm.
In the dying minutes City were desperately unlucky not to add a fourth goal when Poom made a brilliant double save to deny Fowler and Belmadi.