In a retelling of the Doom/Beyonder fight, it showed Doom (with Galactus' powers) forcing the Beyonder to his knees and stealing his powers. Which is a little different than what happened in the actual Secret Wars.
http://i238.photobucket.com/albums/ff240/Branlactus/Raw%20power/Spider-ManamptheSecretWars4018-19.jpg
http://i238.photobucket.com/albums/ff240/Branlactus/Raw%20power/Spider-ManamptheSecretWars4020.jpg
Galactus (and others but Galactus was the most powerful used) was used to fight against Eternity and other beings in a fight that greatly weakened the Marquis of Death:
http://i238.photobucket.com/albums/ff240/Branlactus/Raw%20power/ff345.jpg
http://i238.photobucket.com/albums/ff240/Branlactus/Raw%20power/ff346.jpg
http://i238.photobucket.com/albums/ff240/Branlactus/Raw%20power/ff347.jpg
Was stated to be the biggest and scariest bad guy out of all the villains that could have shown up:
http://i238.photobucket.com/albums/ff240/Branlactus/Raw%20power/Statements%20of%20power/1985-023.jpg
The Avengers and Silver Surfer couldn't get through his force field:
http://i238.photobucket.com/albums/ff240/Branlactus/Energy%20manipulation/1985-015.jpg
http://i238.photobucket.com/albums/ff240/Branlactus/Energy%20manipulation/1985-016.jpg