Josh Maja scored the only goal as Sunderland beat Blackburn Rovers at Eppleton Colliery on Friday night.
The goal came after 30 minutes in a half the home side dominated, although Rovers fought hard after the break for an equaliser.
A boost for Sunderland was a first return to action this season of Sebastian Larsson, who played the first 45 minutes.
REPORT: Good news on the injury front as Larsson returns in U23s' win... https://t.co/LGuHIH91wR— Sunderland AFC (@SunderlandAFC) November 4, 2016
Sunderland moved above Rovers in Group B on four points, while Burnley and Cardiff City will play their second match in the group on Tuesday, 8 November.