Chennai: T.T.V. Dinakaran, nephew of the jailed V.K. Sasikala Natarajan, has won Jayalalithaa's seat by a huge margin, boosting his claim to Amma's legacy and stunning the ruling AIADMK faction in spite of central agencies snapping at his heels.

Running as an Independent, Dinakaran defeated his nearest rival, the AIADMK's E. Madhusudanan, by more than 40,000 votes in R.K. Nagar, which Jayalalithaa represented when she died last year.

Dinakaran bettered Jayalalithaa's margin in 2016. "We are the true AIADMK, the people of R.K. Nagar have elected Amma's successor," he said.

The result is expected to cause an upheaval in Tamil Nadu politics if the fence-sitters in the AIADMK gravitate towards Dinakaran, who has been sidelined in the party.

The tally suggested the Opposition DMK was still in the doghouse. Dinakaran bagged 89,013 votes, the AIADMK 48,306 and the DMK 24,651. Of the 59 candidates, all except Dinakaran and Madhusudanan lost their deposits.

Earlier this year, the AIADMK factions of chief minister E.K. Palanisamy and O. Panneerselvam had merged and removed Jayalalithaa's long-time live-in aide Sasikala, in jail in a disproportionate assets case, as party chief and Dinakaran as her deputy.

None would have dreamt of such a massive win for Dinakaran, who has been hounded by not only his own party but also various central agencies, including the Enforcement Directorate.

An Independent winning an election in Tamil Nadu is rare, with Dinakaran's victory being the first such instance in 16 years. Also, this is the first time a ruling party candidate has lost a by-election in the state since 2004.

There had been allegations of bribing voters, but the Election Commission refused to postpone the by-election, which was held on December 21. The voter turnout in the constituency of 2.28 lakh was 77.68 per cent.

For the ruling AIADMK, R.K. Nagar represents the legacy of Jayalalithaa and retaining it was vital to establishing that Palanisamy and his team were in control. But Madhusudanan, the party's presidium chairman, could not secure even 60 per cent of what Dinakaran got. Madhusudanan had held the seat between 1991 and 1996.

Hailing from Chennai, Madhusudanan is said to wield influence among Telugu-speaking people, who have a sizeable presence in R.K. Nagar. However, even the merger of the Palanisamy and Panneerselvam factions and the AIADMK securing its two leaves' symbol could not help him.

During the campaign, the AIADMK had accused Dinakaran and Team Sasikala of hiding facts about Jayalalithaa's illness and death. The Sasikala camp countered the charges by releasing on poll eve a video of a person resembling Jayalalithaa, purportedly showing her at the hospital a few days before her death, to claim she had been recovering.

The video had focused on the patient's legs to counter the charge that they had been amputated.

However, the Election Commission ordered TV channels to take the video off the air, calling it a violation of the poll code.

Making it a triangular contest, the DMK had fielded Marudhu Ganesh, a resident of R.K. Nagar who was seen by many as a strong candidate. But his performance was miserable despite the Congress, VCK, MDMK, CPI and the CPM backing him.

It has become evident that even the most ardent DMK cadre has deserted the party, which used to get at least 30 per cent votes in every election. Not only did Ganesh forfeit his deposit, it was unclear what happened to the votes of the parties that had backed the DMK.

The BJP, which has shown keen interest in Tamil Nadu politics, too put up an abysmal show, securing less votes than even the Nota option. BJP MP Subramanian Swamy sought an "introspection" by the party.

Lok Sabha deputy Speaker and AIADMK leader M. Thambidurai attributed the DMK's poor showing to the so-called 2G scam. DMK leaders A. Raja and Kanimozhi, the daughter of party patriarch M. Karunanidhi, were acquitted last week by a CBI court that said there was no scam at all.

Political analysts began predicting that the R.K. Nagar result could be the beginning of Palanisamy's end. They said Dinakaran would now focus on the removal of both the chief minister and his deputy, Panneerselvam.