Simplify the following text for a Grade 11 native English-speaking person.
Original: Australia defeated Sri Lanka in the final by 53 runs ( D\/L ) , in farcical light conditions , extending their undefeated run in the World Cup to 29 matches and winning three straight World Cups .
Simplified: The cause of death was heart failure , Australia defeated Sri Lanka in the final by 53 runs ( D\/L ) , extending their undefeated run in the World Cup to 29 matches and winning three straight World Cups .