Blues took the lead in the first half through winger Matt Birley but the hosts levelled through Chris Brown to send the sides in all square at half time.
It took Blues just ten minutes of the second half to regain the lead however, Marcos Painter heading home to give them a 2-1 advantage.
Carl Motteram secured the three points for Keith Bertschin's side on seventy minutes to put Blues top of the League table going into the derby game against Aston Villa's second string at St Andrew's on Monday night.
Blues Reserves: Bennett, Parratt, Lazaridis (Blake, 73), Martin Taylor, Painter, Clemence, Birley, Alsop (Hinks, h/t), Till, Barrowman, Motteram.
Sunderland Reserves: Alnwick, Lynch, Dodds, Thornton, N. Collins, D, Collins, Ryan, Leadbitter, Brown, Bridges, Welsh.