Advice needed: Clown Fish issue

[Mahawka]

Advice needed Clown Fish

I have a situation where my clown fish has been fighting for 24 hours now. Just some background information. Clown 1 has been in my tank for about 1 month (alone). He/she is about 6-9 months old and has hosted in my RBTA.
1 month later I introduced a 2nd clown fish to the 10 gallon nano. Clown 2 is about the same age and about the same size as clown1. At first the 2 fish were getting along well. They would swim together but sleep separately. Clown1 would go back in his RBTA at night and clown2 would sleep beside the heater. I did not see any fighting or aggression from the two.

After work one day (about 1 week later after clown2 was introduced), to my surprise I see clown 2 in the RBTA and chasing clown 1 away. As the day progressed the fighting became worse. Clown 1 would repeatedly dash in to the RBTA but clown 2 would chase him out. During this process I can see clown 2 being the more dominant one. Clown 2 is doing all the nibbling where as clown 1 is just trying to go back to his RBTA. This process has been going on for about 24 hours. Clown 1 looks exhausted and breathing really heavily. No one is doing a submissive twitch.

What do you guys think ? Is this normal? are they just pairing up ? or is this more of a territorial thing?
Should I leave the clowns in the tank ? or maybe remove one?


Thanks !