After a goalless first half, it only took two minutes of second before Emil Forsberg broke the deadlock.
Forsberg received a return from Frankfurt goalkeeper Kevin Trapp which he sent in right up the crossbar to 1-0.
This is the first goal for the Swede, who has been injured for a long time, since 20 January.
He is sixth so far in the league this season.
Forsberg missed six games at the beginning of the year but was back in play on 21 February.
After 61 minutes, Frankfurt equalized through Daichi Kamada.
Leipzig chases Bayern Munich, who top the Bundesliga table with 58 points.
Leipzig is second right now at 53 points.
The match is in progress. The text is updated.