By reading @krishna's comment on this answer, come to know that lord Hanuman was not that powerful to fight with Ravana.
So when did Hanuman fight with Ravana?
Read the comment below
Hanuman fell into a swoon when hit by Ravana and when by Hanuman, Ravana recovered quickly and got up to fight again. Hanuman salutes Ravana for his energy and strength and declines to fight Ravana any further.
Another thing I want to ask is Did Vali have the power of 60,000 elephants? If so How did he get such power?
I already know about the boon to take half of the energy of his opponents, but power of 60,000 elephants is a different thing.
Another question would be when did Vali fight with Ravana?
Vaali, just plucked Ravana and put him in his arm pits and roamed around the world.
What is the story behind this?