The Whites deservedly deservedly won 3-1 against a team expected to push them to the limit.
Leeds have shown a touch of real class at times, with an eight-game winning streak on home soil to take them to the top of the Championship ahead of tonight's trip to Millwall by promotion hopefuls Sheffield United.
United manager Daniel Farke said: “I think it was definitely a deserved victory in the end.
“I would also like to congratulate Middlesbrough for a great performance away, a really positive performance. I think we played a great team today, so I think today’s win was even sweeter.”
Leeds vs Boro has been a match that has produced a lot of goals in recent years and this one was no exception.
It took just 14 minutes for United to take the lead. After Dan James's cross caused havoc, visiting goalkeeper Seny Dieng fell onto his back but was able to kick the ball to Willy Gnont, but the ball went over the line.
There may have been an element of luck in the goal, but it was the reward for a fast start led by James that Boro were unable to contain all night.
Smooth Leeds kept up the pressure while their defenders nullified Boro's attack, which had scored 18 goals in five games in November.
Leeds had two big chances to extend their lead just before half-time when Brenden Aaronson smashed the ball into the stands from a good position and Gnont drew good saves from Dieng.
The Teessiders were passive in the first half, but came out more aggressive after the break. In the 54th minute, a corner kick was taken by Illan Meslier, who made a flying save to deny Riley Magley's shot, but Max Uber headed it into the net.
The momentum was starting to tilt in Boro's favor, only for Meslier to brilliantly deny Liverpool's highly-rated teenage loanee Ben Doak.
Leeds gradually regained control of the match as Joe Rothwell and Ao Tanaka began to move the Whites further up the pitch in attacking areas.
James had a meek shot saved, but seconds later he made no mistake. Substitute Joel Pillow powered the ball into the corner of Boro's net in the 74th minute.
There was no turning back for Boro after that and United were able to pull off a good performance and claw their way back to a point, before an unselfish move from Tanaka led to Aaronson scoring a well-timed follow-up and a selfless goal.
An added bonus for Leeds was the return of substitute Ethan Ampadu for the first time since suffering a knee injury in September.
United are in good form at home (28 of 33 points) but need to improve on the road, starting with Saturday's game against Preston.