Devi Mahatmya by Abhinav Agarwal - 10
Devi Mahatmya - Markandeya Purana, tr. by Bibek Debroy
Chapter 10 (Ch 87 in the book)
With Nishumbha killed, Shumbha taunted Durga that she had been able to fight as long as she had only with the help of many other gods and goddesses. The goddess responded that she was only one, all others were her own manifestations. All the other goddesses entered into her and only Ambika remained.
The battle began again between the goddess and Shumbha. Divine weapons were unleashed, by both Ambika and Shumbha the daitya. His weapons, however, were destroyed by Parameshvari with a mere humkara! The asura used arrows, sword, to attack. All of them were, however brought down by the goddess. She then destroyed his chariot, slew his horses and charioteer. Shumbha rushed at Chandika to bludgeon her with his bare fists, striking her chest with his fists. The goddess, however, was unmoved and slapped the asura, who fell down. Rising again, he grabbed the goddess and rose up in the sky, where the battle between the two continued.
After a long battle in the skies, Ambika hurled the asura to the ground. Before he could get up to strike again, she pierced him with her trident, finally killing him.
With his death, the entire world turned pleasant. The skies became clear, rivers began to flow again, a gentle breeze started to flow, sacrificial fires resumed blazing.
Reference: Markandeya Purana, translated by Bibek Debroy. Published by Penguin, 2019. The Devi Mahatmya is covered in chapters 78-90 of the Markandeya Purana.