This achievement is unlocked by inflicting a certain amount of damage towards Wesker before the seven minute deadline during your first encounter in the Monarch Room. The easiest method is to use an RPG. Just as the fight starts, run to a blue metal door on the right of the map. Check the door and it will say that it is locked. After checking out the door, a cinematic will begin where Wesker kicks Chris through the door. Right after this cinematic, run to the left up the stairs and then to the end of the corridor. Go up against the wall and lean out with your RPG in hand. Just when Wesker comes up the stairs, shoot a rocket at him. He will catch it, then struggle for a couple seconds. Shoot another rocket as soon as you can when you see this happening. Both will explode in his face. He will then run directly up to you, but not attack. Instead, he will spin and twirl away, defeated. Do not forget to pick up the Heart of Africa treasure (worth 10,000 gold) during your fight with Jill--it is located between two staircases in the main room.