Don Quixote Volume 1, Chapter 9
The narrator manages to find another source. While at a marketplace in Toledo, he comes upon an old notebook written in Arabic and finds someone to translate it for him. They read a passage that refers to a Dulcinea from Toboso as being the best salter of pork in all of La Mancha!
The book's title was History of Don Quijote of La Mancha, written by Sidi Hamid Benengeli, Arab Historian.
And so we are now able to find out how the battle ended. Don Quijote, after receiving a blow that removes most of his helmet and half of his ear, strikes a blow to the Basque's head that leaves him unable to continue to fight. The ladies in the coach beg Don Quijote to show mercy and not finish him off; he agrees on the condition that the Basque present himself to Dulcinea. They promise quickly.