I believe you are referring to the Abyssinian-Adal war of 1529-1543.

The war causes are pretty simple. The Adal sultanate and Mogadishu sultanate (roughly Somalia) wanted to conquer Christian Abyssinia (Ethiopia)

During the course of the war the Adal army under Imam Ahmad's proved to have the advantage and defeated several Ethiopian armies. In 1540, the emperor of Ethiopia was killed, the heir captured and Empress besieged in the capital. 3/4 of Ethiopia conquered. In 1542 the Portuguese and ottomans joined in the war.

At the Battle of Wolfa, Imam Ahmad defeated the Portuguese expeditionary force of around 290 men under De Gama; who was beheaded by the Imam. It should be noted that the Imam had several thousand men.

February 21, 1543. The battle of Wayna Daga. The combined Ethiopian-Portuguese army defeats Ahmad who is killed in battle. They soon defeated a second Adal army. With this victory the tide turned in Ethiopias favor and a peace was made and all conquered territory returned to Ethiopia. Both realms extremely weakened by the war.

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Secondly, we need to be careful about terminology. Superpower is a recent term that applies to very few countries ( 2 in fact).

The Portuguese at their height were a Great Power and a World Power by extension. It's a bit semantic but the term becomes watered down and meaningless with constant usage.

Thirdly, no colonial power was undefeatable, especially during the early renaissance when several powers World wide had near as powerful armies, especially locally.

And even during the height of British power in the late 1870's a Zulu army of 20,000~ warriors destroyed a British army of a nearly 2,000 men at the Battle of Isandlwana.

So we should be careful about thinking about the past in stereotypes