Theory:

     Mesmerised with the pahalwan’s extraordinary strength, the ghost did as he was told. Alarm shot through him. This man could easily vanquish him in a wrestling bout in the dark. But perhaps, he could be tricked in other ways. Assuming a servile manner, the ghost said, “Friend Vijay Singh, it is an honour to meet a man like you! I admit to being defeated. But where will you go tonight? Rest in my house. You can leave tomorrow.”
 
     Now thoroughly elated, Vijay Singh replied, “I cannot refuse your hospitality but tomorrow you will go with me as my prisoner. I must display the trophy of my victory to my people!” The ghost bowed in agreement, but silently vowed to kill Vijay Singh in the night. He led him to his house in the cave.
Explanation:

The ghost was amazed and attracted towards the exceptional strength of Vijay Singh. Vijay Singh looked like an abnormal person and special for the ghost. All these days, it had seen only the average human beings. Suddenly, a plan strikes the ghost's mind. Realising Vijay Singh's strength, the ghost concluded that his enemy could not defeat Vijay Singh through fight. Instead, he can be cheated and won in a tricky way.

The ghost had a plan in its mind to cheat Vijay Singh to win him. Though the ghost spoke to him in a much pleasing manner, he had a plan in its mind. It conveyed that it was an honour for the ghost to meet such a strong person like Vijay Singh. It openly admitted to have been defeated by him. The ghost trickily spoke to Vijay Singh demanding a night's stay in its place. It told him that Vijay Singh could leave the next morning after having rest in its place since it was the night time.

Vijay Singh felt proud of his achievement. He then informed the ghost that he was pleased with the ghost's hospitality. Still, he raised a demand to accept the ghost's invitation. The demand was Vijay Singh wanted the ghost to be his prisoner the next day. Vijay Singh also gave the reason behind his demand. Its because he wanted to prove to people that he had done something unusual.

The ghost had not refused but accepted Vijay Singh's demand. Though it accepted Vijay Singh's demand, inwardly it promised itself to kill him during his night stay in the ghost's place. He took him along to its house inside the cave.
 
The haunted house .jpg
The haunted house
 
Meaning of difficult words:
 
S.No
Words
Meaning
1.
Mesmerise
To hold or attract someone completely so that they cannot think of something else
2.
Bout
A short period of involvement in an activity
3.
Vanquish
To defeat someone completely
4.
Assuming
Believing something to be true without any proof
5.
Servile
Wanting to serve and please someone 
6.
ElatedExtremely happy and excited that something expected has been achieved
7.
Hospitality
Showing kindness towards your guests and strangers
8.
Bow
To bend your head or body to accept something
9.
Vow
To promise to do something
Reference:
National Council of Educational Research and Training (2006). A Strange Wrestling Match: Indira David (pp. 43-51). Published at the Publication Division by the Secretary, National Council of Educational Research and Training, Sri Aurobindo Marg, New Delhi.