Pro tip to winning the game: destroy the enemy Nexus.

You don't win from getting the most kills. You don't win from stealing baron. You don't win from a 10k gold advantage. You don't win by dealing more damage.

You win by blowing up the enemy Nexus.

The other things help, but they are not necessary.

Let this be a lesson to everyone:

http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/1935876406/213933916?tab=overview