Lucien Favre's side, who lost at home to Cologne last weekend but qualified for the Champions League last-16 in midweek, were without the injured Erling Haaland and put in another fitful performance.

The 18-year-old Reyna levelled in style on 56 minutes after Daichi Kamada's opener.

Third-placed Dortmund sit three points behind leaders Bayern Munich, who host second-placed RB Leipzig in an enticing table-topper in Saturday's late game.

Freiburg and Borussia Monchengladbach drew 2-2, as did Cologne and Wolfsburg, while Arminia Bielefeld beat Mainz 2-1 to leapfrog their rivals into third-from-bottom.

Dortmund boss Favre decided against replacing Haaland with 16-year-old wunderkind Youssoufa Moukoko, who started on the bench with Julian Brandt preferred up front.

But it was hosts Frankfurt who made the better start and Japan's Kamada struck on nine minutes after springing the offside trap and staying calm to score.

Dortmund had their chances in the first half with Jadon Sancho shooting just wide in another frustrating performance.

Favre threw on Moukoko, whose youth scoring record is remarkable, at halftime for midfielder Mahmoud Dahoud.

Youthful Dortmund pushed hard and levelled through a superb piece of skill and finish from Reyna. He found the top near corner with a rocket having skipped past a challenge like a veteran.

"You could tell in the first half that we had some players who had been out injured quite a bit. The rhythm was missing," Dortmund goalkeeper Roman Buerki told Sky.

"In the second half we didn't play too badly and with a bit of luck we could have won."

Gladbach warmed up for a big week in the Champions League with a draw in Freiburg.

Breel Embolo fired home first time after a fine move to put them ahead.

Freiburg, who have a strong record against Gladbach, equalised when Philipp Lienhart headed in after an overhead kick from Baptiste Santamaria.

The hosts then took the lead through Vincenzo Grifo's penalty but Alassane Plea levelled soon after on 50 minutes with a stunning strike. Both sides had big chances to win it late on.

Australian Associated Press