Rafael Nadal won the French Open Tennis Tournament in 2022 by defeating Casper Ruud. It is important to note that the other options, Austin Krajicek, Ivan Dodig, and Joran Vliegen, were not the opponents Rafael Nadal faced in the final match.

Option 1: Austin Krajicek - this is not the correct answer. Austin Krajicek did not play against Rafael Nadal in the French Open Tennis Tournament in 2022.

Option 2: Ivan Dodig - this is not the correct answer. Ivan Dodig did not play against Rafael Nadal in the French Open Tennis Tournament in 2022.

Option 3: Casper Ruud - this is the correct answer. Rafael Nadal defeated Casper Ruud to win the French Open Tennis Tournament in 2022.

Option 4: Joran Vliegen - this is not the correct answer. Joran Vliegen did not play against Rafael Nadal in the French Open Tennis Tournament in 2022.

To summarize, Rafael Nadal won the French Open Tennis Tournament in 2022 by defeating Casper Ruud, not by defeating Austin Krajicek, Ivan Dodig, or Joran Vliegen.