Both teams came into this matchup in exceptional form, with the hosts unbeaten in eight games and Stuttgart on a run of six straight victories domestically.
And things were pretty even in the opening 10 minutes as both teams had chances, with David Raum firstly stinging the palms of Alexander Nubel inside three minutes, before Deniz Undav sent a glancing header narrowly wide of the post moments later.
The two continued to tussle as the first half wore on, with chances falling at both ends of the pitch. Maximilian Mittelstadt unleashed a powerful effort which looked destined for the top corner, but Peter Gulasci produced a spectacular save to deny the German international.
But just as it looked like neither side would break the deadlock, Leipzig went ahead in fortuitous circumstances, when Diomande was given the freedom of the right flank to drift into the box unopposed, and his ball across the face of goal was turned in by the luckless Jeff Chabot.
Going ahead right on half-time seemed to give the home side a boost in energy as they came out for the second half, and that was confirmed as they doubled their lead within eight minutes of the restart.
Diomande was once again picked out on the right flank, only this time, he decided to drift inside and brilliantly beat Nubel at his near post.
Sebastian Hoeness made a double change in response to falling two behind, and one of those introduced, Tiago Tomas, repaid the faith of his manager after cutting the deficit within seven minutes of entering the contest.
After breaking through the offside trap, the forward rounded the goalkeeper before firing in his third league goal of the season.
However, the away side weren’t able to create further momentum to level the scoreline, with just the one shot on target in the second half.
Instead, Leipzig added a third goal in stoppage time to confirm the result, which sees Stuttgart fall to their first league defeat since September. A third consecutive league win moves Ole Werner’s side up into second and two points behind league leaders Bayern Munich.
Flashscore Man of the Match: Yan Diomande (RB Leipzig)