Ywain (not Gawaine, though that’s an easy mistake to make) was a young pup of a knight but an ambitious one, as befit a child of Urien-king, and set out one day to make his name. Also to revenge an injury that had befallen his cousin Calogrenant, and to put paid to the scorn Kay the Seneschal had heaped upon his head, and eke again to satisfy his curiosity about a magic spring, a fabulous pine tree full of joyous birds, a furious knight, and a beautiful lady or two. In truth were there several leads pulling him along this path; you may choose which one best pleases you, and who could say you lie?
As was the custom, Ywain wandered for a while through lands blasted and strange and endured adventures picturesque but not quite worthy of a tale in themselves, until he came to the magic spring and engaged the furious knight in battle. Quite a fight it was, and only ended when Ywain struck the knight such a blow on the head that his sword came out bearing brains, ye gods. Not enough to kill the knight, or at least not before a merry horserace across uneven ground and into his hidden fortress, but enough to see him drop dead just past the portcullis. So far so good.
Things would have gone badly here for Ywain, valiant and comely as he was, only he’d spoken gentle to a random lady at a party once years before, and so he comes out of it with a rich wife and a new castle. Oh, not to the lady from the party — your man marries the widow of the knight he murdered with the party woman as a go-between. Love, amirite.