However, they increased the gap with second-placed Bayern Munich to seven points after the champions’ shock loss at Bayer Leverkusen.
Borussia Dortmund initially looked impressed by Eintracht Frankfurt’s tough, physical game but that lasted for only 20 minutes.
The visitors put their foot on the gas and Marco Reus scored the lead after good early work from Raphael Guerreiro in the 22nd minute, also hitting the woodwork a little later.
In-form Luka Jovic drew the hosts level in the 36th minute and both teams had their share of missed goalscoring chances in the second half.
The draw was still enough to lift Borussia Dortmund to 49 points, seven ahead of Bayern Munich, who are stuck on 42 points after their 3-1 defeat at Bayer Leverkusen.
Third-placed Borussia Moenchengladbach, in action against Schalke 04 later on Saturday, are on 39 points.