Rotherham took the lead in the 19th minute when captain Ollie Rathbone struck a low effort into the bottom corner from the edge of the box.
The hosts then added a second when Shane Ferguson broke down the left before converting another low effort.
Leeds loanee Joe Gelhardt then scored his first Sunderland goal just after the hour mark, but it was too little too late.
Here’s how Phil Smith rated the Sunderland players against Rotherham:
Leeds loanee Joe Gelhardt then scored his first Sunderland goal just after the hour mark, but it was too little too late.
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