As he gained a lead in the constituency, Tharoor said he “feels like a batsman who has scored a century while his team has lost.”
Tharoor was in a close contest with BJP’s Kummanam Rajasekharan, a former state party president who recently stepped down as Mizoram’s governor to contest the polls.
Tharoor had rejected the exit polls predictions on Sunday, saying he would wait for the real results on 23 May.
In 2014, Tharoor had retained his seat in the 2014 election with margin of just 15,470 votes over veteran BJP leader O Rajagopal.
The 2019 was seen as the BJP’s biggest chance to open its account in a state in which it has never won a seat.
Tharoor made his political debut in 2009 as Congress candidate from the high-profile Thiruvananthapuram constituency, after he left the United Nations and returned to India.