Overturn a downward spiral situation

Concentrate on the task at hand.
Keep your undivided attention to what you are doing, even if the results are not yet favorable to you.

Flow with whatever outcome.
Be ready to integrate every ripple of life into your creative moment.

Relax at critical moments.
Taking deep breaths, for example, could help you snap out of a bad state of mind and do better.

Leave the competition hall and take a short stroll in the yard if the game permits this.
You are likely to return with a brand new state of mind.

Study your opponents closely.
Taking a few minutes to study an opponent close can help you take advantage of their weaknesses to your favor.