Fun question. I think I've got a solution; let's step through the process of implementing it. Naturally it will involve a series of select questions and constructed lists.
First, let's start by creating a predefined list with all the items you want to be involved in the "tournament." Then we'll need to create our first constructed list. I'm guessing we're just choosing two items randomly:
("list1" being the name of the predefined list.)
Create a select question that uses that constructed list, then we can add our second constructed list. This constructed list should have these instructions, with an optional additional Randomize at the end if you want the previously-selected item to not always appear first in the next question:
Insert(1, list1, Q1)
("list2" being the name of the first constructed list, and "Q1" being the name of the first select question.)
Now we can start continuing this process as far as we need it. Each constructed list will have the same instructions as what exists in the second code block, with two modifications:
* Repeat line 2 with each additional constructed list, removing the items of all previous constructed lists.
* Update line 4 to replace "Q1" with the name of the previous select question.