Rahman, 48, thanked his fans and team for making the gig, which coincided with India's 69th Independence Day, such a success.
"O2 London management just told me that it was a sold out concert... Thank you for your extraordinary love last night... My team and I were thrilled performing for you... See you again soon," Rahman posted on Facebook.
The double Grammy and double Oscar winner returned to The O2 after a gap of five years.
Singers Neeti Mohan, Javed Ali, Karthik, Jonita Gandhi and Hriday Gattani also performed alongside Rahman.