Next morning Arthur and his assembled knights ride forth, and towards the back of the group Sir Launcelot and Sir Lavaine, disguised as Sir Tirre and Sir Lavaine, ride out too. Malory seems to have lost track of the fact that Arthur left Camelot to go to this tournament, because now he says that the tournament takes place in Camelot. We can disregard that, though, on account of it’s nonsensical. He also claims that everyone gets together for the tournament and then they wait until Assumption Day, which is bull hockey, because Malory just last chapter said that this tournament was scheduled for two weeks after Assumption Day.
What we can be sure of, though, is that there’s a big jousting tournament. The knights divide up into two teams: Arthur and Anguish and Scotland on one side, and Northgalis, Northumberland, Galahad-but-not-the-one-you’re-thinking-of, and Mister 100 on the other. Everyone knows that these two teams are a very uneven match; Arthur’s team has all the best knights, and Mister 100’s team just has Mister 100 and a bunch of losers.
Long story short, Arthur’s knights beat the tar out of Mister 100’s team, until Sir Launcelot joins the fight on Mister 100’s side. Launcelot rampages and incapacitates a big pile of his supposed comrades, until Sir Bors and the rest of Launcelot’s extended family get together in a wedge formation and team up to take Sir Launcelot out. Launcelot loses his horse, and Sir Lavaine gets him a new one! In the process Sir Lavaine beats the tar out of Sir Alisander, with is another flagrant continuity violation inasmuch as Sir Alisander (whose tale is told in an extended flash-foward in Book X, chapters 32-38) is a child at this point in the timeline.