Two things can happen when the pressure mounts.
1. You start to think and analyse your every move. This seems like the right thing to do but it almost invariably leads to choking.
2. You keep playing and don’t let distractions settle.
Option one happens for most by default.
Option two takes a clear head and some courage. You can’t panic when the pressure hits home. Take a deep breath, relax and focus on what you want to do. Anything else is a waste of time and energy.