"Thank you to all the voters of Delhi. Thank you to all the party workers for their hard work… We respect the mandate of people. @ArvindKejriwal congratulations to you," he posted on Twitter in Hindi.
Tiwari had asserted that his party will win more than 45 seats in the 70-member Assembly and form the government.
The Aam Aadmi Party on Tuesday registered wins in at least 10 constituencies till late afternoon, with its prominent faces Manish Sisodia, Atishi and Raghav Chadha emerging victorious from their respective constituencies.
The AAP appeared to be heading back to power for a second term in Delhi, with the party leading in 63 of the total 70 seats, and the BJP ahead in seven seats, according to the Election Commission figures.
The elections to the Delhi Legislative Assembly were held on February 8.