Make sure the race is set on ten percent difficulty. Then, cause a crash on lap four. If done correctly, there should be a caution. Go into the pits, and ignore that fact if no one else also enters. You will probably be last, but there will soon be another caution and the leaders will come in. Stay out and do not pit. After the stop, you should be in first or second place. You will run low on gas, but you will not run out. Block and you will be able to win.