The grouping's presidential candidate N Sai Balaji won after bagging 2,161 votes.
Sarika Choudhary bagged 2,692 votes and was elected the vice president.
Aejaj Ahmed polled 2,423 votes and won the post of general secretary. Amutha was elected the joint secretary with 2,047.
The Left-backed All India Students' Association (AISA), Students' Federation of India (SFI), Democratic Students' Federation (DSF) and All India Students' Federation (AISF) have come together to form the 'United Left' alliance.
Besides the Left bloc, there were candidates of Akhil Bharatiya Vidyarthi Parishad (ABVP), which is the student wing of the Rashtriya Swayamsevak Sangh (RSS), the Congress-affiliated NSUI (National Students' Union of India) and BAPSA (Birsa Ambedkar Phule Students Association).
The voter turnout in the keenly contested JNUSU election on Friday was 67.8 per cent, believed to be the highest in six years. Over 5,000 students cast their votes.