Benjamin Sesko scored an early brace and Peter Gulacsi saved a penalty as RB returned to winning and scoring ways in the Bundesliga with a 4-0 demolition of Augsburg on Saturday.
Coming off 0-0 draws against Union Berlin and St Pauli Hamburg, Leipzig wasted no time and were 2-0 up within 15 minutes from Sesko's low shot and header at the far right post.
Leipzig keeper Gulacsi saved Jeffrey Gouweleeuw's spot kick in the 27th before Lois Openda made it 3-0 seconds after the restart off Xavi Simons' defence-splitting pass. Simons fired the fourth himself in the 57th into the near corner.
Leipzig rose into second, one point behind Bayern Munich, who host champions Bayer Leverkusen in the big game of matchday five later on Saturday.
German striker Deniz Undav salvaged a stoppage time 2-2 in Wolfsburg for 10-man VfB Stuttgart in a turbulent encounter.
Jonas Wind put the hosts ahead on the counter in the 20th but Enzo Millot got the 1-1 equalizer for last season's runners up in the 32nd on the rebound of his penalty saved by Kamil Grabara.
Mohamed Amoura restored Wolfsburg's lead in the 68th into the far right corner, five minutes after Stuttgart's Atakan Karazor had to go after a second booking.
Amoura was shown a straight red in the 73rd which was rescinded upon review but Wolfsburg failed to hold on to full points because Undaz pounced at the far post in the seventh minute of stoppage time.
Freiburg failed to draw level with Bayern when they were shocked 3-0 at home by promoted St Pauli who got a first season victory. Heidenheim won 2-0 at Mainz while Borussia Mönchengladbach beat Union 1-0.