If you are competing with someone and your strength, skills and confidence is the same as your his... the one who has the stronger focus will win. Because at one point during the competition, someone will break mentally, someone will experience fatigue. Someone will gas out, not because he is not strong but because his focus shifts from competing to wanting to rest.
Someone will give up and you have to make sure that it is not you if you really wanted to win. You must be super focus on taking the prize and you must be willing to pay the price. It is like feeling the pain but still pushing forward.
A lot of people were very strong, a lot of people were very skilled but they can't win because their focus changes on the middle of a challenge. They freak out when adversity strikes in. They become weak when high amount of pressure is felt.
If you are so focus in winning, you cannot feel the pain, you will forget what is going on inside of your body. You will just live the moment and move as long as you can. You mindset will never change, your motivation becomes stronger as the challenge goes on.
The key here is forget about your emotions, never mind of you are feeling pain, exhaustion or running out of gas. A person will never stop if his willpower is unparalleled. Always think about winning and never entertain an idea of losing. You need to complete like a real competitor, you need to fight like a real warrior. Forget about resting because you can always rest after the challenge. Focus on now, focus on execution. Yes, it is easier said than done but it can be done.