Leipzig capitalised on Bayern's 2-1 defeat at Eintracht Frankfurt 24 hours earlier. A long-range goal by captain Marcel Sabitzer gave second-placed Leipzig a first-half lead in Berlin. A superb second-half strike by defender Nordi Mukiele and a header from centre-back Willi Orban sealed the victory.
"It was a very important three-pointer," Sabitzer told Sky. "It's a two-horse race now, but we can't just talk about it -- we have to stay in it, be focused and then at the end, it could be enough."
Leipzig bounced back from their midweek defeat by Liverpool in the Champions League with a clinical display. Sabitzer struck at Berlin's Olympic Stadium when his shot from 30 yards out crashed in off the crossbar on 28 minutes. After US midfielder Tyler Adams robbed Matteo Guendouzi of possession in Hertha's penalty area, Mukiele smashed home the second goal on 71 minutes.
Orban headed home Sabitzer's cross six minutes from time to seal Leipzig's fourth straight league win.
In contrast, Hertha are winless in their last eight league games. They are 15th in the table, but only goal difference keeps Hertha out of the relegation play-off place as they are level on 18 points with Arminia Bielefeld.