The ruling AIADMK was on the winning track Sunday in the Yercaud constituency in Tamil Nadu, with its candidate P. Saroja leading over DMK's V. Maran by over 4,800 votes.
The Election Commission said that of the 15,729 votes counted, 432 voters had exercised the 'None of the Above' option.
Eleven candidates were in the fray in the Yercaud assembly constituency where the by-election was held Dec 4.
The election in the hill station, around 360 km from here, was announced after AIADMK legislator C. Perumal died in July, bringing down the AIADMK strength in the 235-member assembly to 150. Saroja is Perumal's wife.
This is the fourth assembly by-election in Tamil Nadu after the AIADMK took power in May 2011.
It won all three earlier by-elections -- in Pudukottai, Sankarankoil and Tiruchirapalli (West) constituencies.