The BJP's Sunil Soren defeated Shibu Soren (in picture) by 47,590 votes.
The ruling Bharatiya Janata Party (BJP) maintained the 2014 tally this year too by winning 12 of the 14 Lok Sabha seats in Jharkhand along with its ally.
In 2014, the BJP fought alone and won 12 seats. This year, the BJP gave the Giridih seat to its ally, All Jharkhand Students Union (AJSU).
The BJP lost its Singhbhum Lok Sabha seat but snatched the key Dumka seat from the Jharkhand Mukti Morcha (JMM).
This is the first time the BJP has won the Dumka Lok Sabha seat since Jharkhand was formed. The constituency comes under the Santhal Pargana division that has been a JMM stronghold for the last 30 years.
Along with Dumka, the Godda and Rajmahal seats also come under the division.
JMM President Shibu Soren has won all the elections from Dumka since 1991 except in 1998 and 1999.
The BJP's Sunil Soren defeated Shibu Soren by 47,590 votes.
Sunil Soren, who was once a disciple of Shibu Soren, has been fighting the seat since 2009. He was defeated both in 2009 and 2014.
Jharkhand Chief Minister Raghubar Das, after taking charge of the state in 2014, focussed on Santhal Pargana. In the by-elections held in the last four years, the BJP did not succeed but his efforts brought the desired result this year.
The BJP managed to snatch the Dumka seat but failed to win Rajmahal. Sitting JMM MP Vijay Kumar Hansdak defeated the BJP by 99,115 votes.
Old age and overconfidence seemed to have worked against Shibu Soren.
"The Soren family has exploited the people of Santhal Pargana for years. The people voted for them but they did nothing for the development of the area. Instead, they amassed land illegally," Chief Minister Das had said at his election rallies.
Shibu Soren has been a grassroots politician who started his political carrier with a campaign against moneylenders in the region.
His campaign freed poor tribals from clutches of usurpers and he became popular as 'Disom Guru' among them.
Another former Chief Minister and Jharkhand Vikas Morcha-Prajatantrik President Babulal Marandi also lost the polls. He was defeated by BJP candidate from the Khuti seat Arjun Munda by just 1,400 votes.