Simplify the following text for a Grade 11 native English-speaking person.
Original: Three weeks later at the Royal Rumble , Triple H successfully defended the World title over Randy Orton at the same event where Batista won the 2005 Royal Rumble match , by last eliminating John Cena , earning the right to participate in the main event of WrestleMania 21 against the champion of his choice .
Simplified: Batista won the 2005 Royal Rumble , last eliminating John Cena , earning the right to participate in the main event of WrestleMania 21 against the World Champion of his choice .