Eintracht Frankfurt have paid the penalty for missing a penalty in stoppage-time, going down in front of their home fans to a 2-1 Bundesliga defeat at the hands of struggling Union Berlin.

Berlin goalie Frederik Ronnow was their hero with the last-gasp spot-kick save as Frankfurt missed the chance to retake third place, allowing in-form Mainz to retain their position in the top three.

"It was a bad day, we are disappointed," Frankfurt coach Dino Toppmoller said.

"We have to shake that off and now focus fully on Thursday. A completely different game awaits us there," he added, referring to the Europa League last-16 match against Ajax. Frankfurt had won the first leg 2-1.

Frankfurt broke the deadlock in the 13th minute through January signing Michy Batshuayi.

Can Uzun's shot from the edge of the box took a deflection and fell for Batshuayi, who completed the well-worked team effort from close range to score his first goal for Frankfurt.

The hosts could have added a second, but Fares Chaïbi's header in the 26th was tipped over the crossbar by the inspired Ronnow.

The missed chance was costly as Leopold Querfeld scored his first Bundesliga goal to level for Union in the 62nd and the visitors turned the game to their favour in the 78th.

A long ball from Union wasn't cleared by Tuta and fell to Jeong Wooyeong, who rushed to the box and curled a precise effort into the net.

Benedict Hollerbach thought he had added a third for Union, but his goal in the 88th was ruled out due to a handball in the build-up.

At the other end, Frankfurt were then awarded a penalty in the fourth minute of stoppage time, but Hugo Ekitike had the spot-kick saved by Ronnow and Union took all three points to now sit 14th, six points away from the drop zone..

In the other game on Sunday, Hoffenheim took a 1-0 lead but conceded a 1-1 draw to bottom side Heidenheim.

Haris Tabakovic broke the deadlock in the 34th with a looping header into the visitors' net and he went close to a second shortly before the break.

But it was Heidenheim who found the target next as Budu Zivzivadze produced a moment of magic and unleashed a stunning shot that arrowed into the top corner.

Neither team left the pitch happy with the point. Heidenheim remain at the bottom of the table, while Hoffenheim are 13th and tied on 26 points with Union.