I remember reading somewhere that the Portuguese found Brazil due to exploration of islands around Africa. This discovery was independent of Spain and Columbus’s discovery prior. I’m looking for that source now and can’t find it.
The Portuguese Pedralvares Cabral (this is the orthography preferred by some Portuguese scholars like Pinheiro Marques) stumbled upon the coast of Brazil in april of the year 1500 when he was performing the manoeuvre known as "grande volta". This consisted in going from Cape Verde distancing yourself from the coast of Africa in order to take advantage of the currents that take you to Good Hope.
A couple months prior, Vicente Yáñez Pinzón reached the coast of Brazil in what today is Mucuripe. He continued his journey following Brazil's coast to the North, discovering the Amazon river in the process. Diego de Lepe reached Brazil in February, and eventually joined Pinzón around the mouth of the Amazon.
I tell all of this in more detail in this other answer.