Leeds' third straight Championship win - in addition to their 2-1 victory over Bolton in the Carabao Cup midweek - maintained their 100 per cent start to the season.
Luke Ayling's header broke the deadlock early in the second half and Kemar Roofe struck his third of the season in fine style in the 72nd minute.
Ayling's first Leeds goal was awarded with the aid of goal-line technology after referee Robert Jones had initially awarded a goal kick.
But Leeds will have to be content with staying second on the Championship table as they remain a point shy of a Middlesbrough, who have played an extra game after easing to a 2-0 victory at Bristol City.
