Sunderland's rousing second-half display secured a convincing victory against an in-form Millwall to move them within a point of the Championship top six.
After an insipid first 45 minutes in which Millwall's Zian Flemming missed a golden chance just before half-time, the Wearsiders hit the front soon after the break when Amad Diallo smashed home an Ellis Simms flick at the back post.
With the crowd fired up, and Sunderland's tails up, Alex Pritchard hammered his angled shot past George Long to double the lead shortly after, following good work by Lynden Gooch to pick him out.