It's easy to lose focus at the very end of a process. The mind thinks about the next stage and the next process, and naturally loses grip on the current situation. The mind can't wait until this current process is over.
But actually this is the point where it is most critical for success or failure. People's perception of success or failure is defined by the last thing they see or experience. All the previous work is considered a sunk cost. Fairly or unfairly, that final moment is what defines a process.
During the run-up to this moment, it's critical to focus on the process even more extremely. Focusing on the process slows down the perception of time and allows for better focus on individual process components. It allows for better distraction management by not focusing on the things outside the process. It ultimately helps concentration and the performance of the final moment.