Congress's Rita Chaudhary defeated BJP's Sushila Sigra in Mandawa.
The ruling Congress in Rajasthan on Thursday increased its tally in the state legislature by one after winning the assembly bypolls to Mandawa while MP Hanuman Beniwal's Rashtriya Loktantrik Party retained the Khinwsar seat.
Both seats had gone to bypolls on Monday.
Congress candidate Rita Chaudhary won the Mandawa seat with a margin of 33,704 votes while RLP candidate Narayan Beniwal won Khinwsar by just 4,630 votes.
Ms Chaudhary defeated BJP's Sushila Sigra in Mandawa.
"I received a huge support from women and the youth this time and I was sure of my victory," Rita Chaudhary said in Jhunjhunu.
Chief Minister Ashok Gehlot and Deputy Chief Minister Sachin Pilot congratulated Ms Chaudhary for the victory.
AICC general secretary Avinash Pande congratulated the government and the party for the win in Mandawa, saying it was the victory of people and party workers.
"The state government has left no stone unturned in fulfilling promises made in the election manifesto. The government is working on loan waiver for farmers and providing jobs to the youth," Mr Pande said in a statement.
For Khinwsar, he said the Congress Party had faced a defeat on the seat in the assembly elections last year with a huge margin, which had reduced in the bypolls, indicating the strengthening of people''s faith in the party.
State Congress president and Deputy Chief Minister Sachin Pilot said the results reflected the hard work of the party workers and the decline in the winning margin in Khinwsar showed that people''s trust in the Congress and its policies was increasing.
In Khinwsar, RLP's Narayan Beniwal won by just 4,630 votes.
He defeated Congress candidate and former minister Harendra Mirdha.
The BJP and the RLP had contested the bypolls in alliance in Khinwsar, where Narayan Beniwal was the candidate.
"This is the victory of people. My priorities will be issues relating to development, farmers, employment, skill development and strengthening of the cooperative system," Narayan Beniwal told reporters in Nagaur.
In the 2018 assembly elections, Mandawa and Khinwsar seats were won by BJP's Narendra Kumar and RLP's Hanuman Beniwal, respectively.
Both were elected to the Lok Sabha in May this year, which necessitated the bypolls.
Rita Chaudhary, who was a Congress MLA from 2008-13, had lost the last year's assembly elections to BJP's Narendra Kumar by 2,346 votes.
On the other hand, RLP convener Hanuman Beniwal had won the Khinwsar seat with a huge margin of 16,948 votes.
Hanuman Beniwal, a former BJP leader, had formed his own party ahead of the 2018-assembly elections and three RLP candidates, including him, had won.
Ahead of the Lok Sabha elections this year, The BJP had forged an alliance with the RLP for the Nagaur seat.
Hanuman Beniwal was elected to the Lok Sabha from Nagaur.
Now the Congress tally in the 200-member state legislature has increased to 107, including six those who had defected to the party from the BSP last month.
The BJP has 72 MLAs in the state legislature.
The RLP now has three MLAs, CPI (M) and Bharatiya Tribal Party (BTP) have two each, Rashtriya Lok Dal (RLD), an ally of Congress, has one MLA and 13 are independents.