Fighting on Foot in the Lists With Spear or Lance

This happened fairly often. There were three main ways this could occur.

1. Thrusting or pushing, lance against lance. The push was a high impact attack, often delivered at a good pace, that could knock a man to the ground. Typically, the lance fight was part of a sequence of combats with different weapons. Examples:
Vannes, 1381
Challenge by Michel D'Orris 1400
Galiot de Baltasin and Phillipe de Ternant Fight on Foot with Lances, 1446
Ayre, Picardy 1494
Challenge of Lady May, Greenwich 1506
Paris 1515 Challenge by the Dauphin in honor of the marriage of the French King “First six foins with hand spears, and after that eight strokes to the most advantage if the spears so long held, and after that twelve strokes with sword” also casting spear and target followed with two-handed sword
Noseroy 1519 “two against two, with strokes of the lance, turning the large end of the said lance; and afterwards they were to fight with sword in one hand, as long as my lords the judges ordered them to.” The next day of combat “each one threw a stroke of the partisan and afterwards they fought with the two handed sword as long as it pleased my lords the judges.” Combat with axes at the barriers was originally planned but apparently not actually fought.

2. Both parties were expected to throw their lances at their opponent, and then continue the fight with other weapons:
Victory of Seven French against Seven English in a Private Combat 1402
D’Ollumen vs. de la Haye 1415
Alvaro Continge vs. Clugnet de Brabant 1415
Maillotin de Bours vs. Hector de Flavy, 1431
A Combat between Sir John de Mello and the Lord de Chargny, 1435
Merlé vs de Chargny 1435
Habourdin vs. de Bearn ca. 1449
Greenwich May 1510 Casting spear and target followed by twelve strokes with a two handed sword
Paris 1515 Challenge by the Dauphin in honor of the marriage of the French King “First six foins with hand spears, and after that eight strokes to the most advantage if the spears so long held, and after that twelve strokes with sword” also casting spear and target followed with two-handed sword
Noseroy 1519 “two against two, with strokes of the lance, turning the large end of the said lance; and afterwards they were to fight with sword in one hand, as long as my lords the judges ordered them to.” The next day of combat “each one threw a stroke of the partisan and afterwards they fought with the two handed sword as long as it pleased my lords the judges.” Combat with axes at the barriers was originally planned but apparently not actually fought.

3. Both parties enter the field each armed with a lance and other weapons to use as they see fit. They can throw the lance or keep it to push and thrust with as long as they can. This was much more common in judicial duels than combats by consent. This scenario was often discussed in German fighting manuals.
Combat between Sir John Anneslie and Thomas Katrington, squire, 1380
How Sir Jacques de Lalaing did arms in Scotland; and of many other particulars in the house of Burgundy. (1449)