Gladbach s Manu Kone, left, and Hoffenheim s Umut Tohumcu fight for the ball during the Bundesliga soccer match between TSG Hoffenheim and Borussia Monchengladbach at Borussia-Park stadium, Monchengladbach, Germany, Saturday Dec. 2, 2023. AP
The French midfielder was left unmarked by the Hoffenheim defense to tuck away Luca Netz’s cross in the 80th minute.
Alassane Plea fired Gladbach ahead from the penalty spot in the 58th before Wout Weghorst equalized two minutes later.
But the visitors were unable to muster a response to Ngoumou’s late goal as they slumped to their first away defeat.
Gladbach, which was unbeaten in three games before losing at Dortmund 4-2 last weekend, was without American forward Jordan Pefok, who tore a thigh muscle in training on Friday. Pefok’s absence gave Ngoumou the opportunity to start.
Also, Leipzig defeated promoted Heidenheim 2-1 and Bochum enjoyed a 3-1 win over Wolfsburg.
Stuttgart hosted Werder Bremen later Saturday.
Bayern Munich’s home game against Union Berlin was called off because of heavy snowfall dumped by a winter storm over much of southern Germany.
League leader Bayer Leverkusen plays Dortmund on Sunday.
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