Black Cats manager Mick McCarthy praised Marcus Stewart for responding in the right way to disappointment after his hat-trick felled woeful Gillingham.
Stewart was unhappy after he was hauled off at Reading in Sunderland's last Championship outing, but his three goals in an emphatic 4-0 victory won his side their first away points and doubled his league tally for the season.
He and strike partner Stephen Elliott benefited from excellent service from Sunderland's midfield which carved up Gillingham at will. But it was the failure of 18-year-old Matthew Jarvis to track marauding left-back George McCartney that proved Gillingham's undoing.
Three times in the first half, McCartney was left in acres of space to fire in crosses that resulted in goals, the first came after just four minutes.
Julio Arca released McCartney whose centre was met by Elliott, Steve Banks did well to parry his shot but Stewart mopped up the rebound for the opening goal.
On 17 minutes the same combination down the left allowed Elliott to score with a diving header from inside the six-yard box.
Stewart bagged his second in 19 minutes, effectively ending the contest after he met another McCartney cross. His first shot hit Elliott in the back, but he smashed home the rebound.
Gillingham's midfield was in disarray with left-winger Danny Spiller often drifting to the right and right-winger Jarvis failing to track back.
Stewart sealed his hat-trick on 68 minutes after intercepting a dreadful backpass from Leon Johnson.
He calming rounded the stranded Banks and coolly slotted the ball into an empty net from a tight angle.