In Renaud de Beaujeu's Le Bel Inconnu, Arthur sets up a tournament to lure the hero, Guinglain, to Blonde Esmerie. He comes incognito, but they recognize him by his shield. At the end of the tournament, he marries his beloved.
In Guillaume le Clerc's Fergus, Arthur entices Fergus out of hiding with a tournament at the request of the Dame de Lodien. Fergus comes incognito, with a shining shield, and defeats the other knights, but he goes away to the forest each night. Dame de Lodien asks to marry the knight with the shining shield, so Arthur sends Gauvain after him, and they are married (116).
Loomis draws another interesting connection between the Dame de Lodien and the names of Lothian and Lyones. It is also interesting to see that the tournament usually takes place near Avalon (Valedon and Avylyon are its variant names), that the Scottish king Agwysaunce is usually in attendance, and that Gaheriet also appears as an incognito knight. It seems that this particular tournament is just another tradition that got swept into the Arthurian legend.