You don’t go into a tournament expecting to win after the first round or day.
What you do in that first round matters. It helps to set you up and put you in a good position.
But it doesn’t win you the tournament.
You could easily flop after a successful first round. Just like you could comeback after a poor performance in the first round.
What wins you the tournament is what happens over the duration of all the rounds.
You have to be focused on the tournament, not just a single round.