Starting the final game half a point behind the Belarussian, the 30-year old Gupta secured a win in 37 moves to seal the top prize with 8.5 points.
The Indian with an ELO rating of 2603 played consistently right through with a loss to fellow GM and compatriot Karthik Venkataraman in round three being the only blip.
Gupta bounced back strongly to score 6.5 points from the last seven rounds, following his third-round loss to Karthik Venkataraman.
Aleksandrov who won the title in 2013 led at the start of every round, had to settle for second spot. Gupta, a five-time Commonwealth champion, took home Rs 6.5 lakh for winning the championship.
Karthikeyan Murali (ELO rating 2606), who was the top-ranked Indian in the tournament and the third seed, beat Florian Kaczur of Hungary in the final round to finish 11th with 7.5 points.
Important Results (10th Round): Aleksej Aleksandrov (Belarus) 8 lost to Abhijeet Gupta (India) 8.5, Pavel Ponkratov (Russia) beat P Shyam Nikhil (India) 7, Karthikeyan Murali (India) 7.5 beat Florian Kaczur (Hungary) 6.5; M Pranesh (India) 7 beat N R Visakh (India) 7.
Levan Pantsulaia (Belarus) beat Kirill Stupak (Hungary) 7, Nodirbek Yakubboev (Uzbekistan) 7.5 drew with Alexei Fedorov (Belarus) 7, Karthik Venkataraman (India) 6.5 drew Alberto David (Italy) 6.5, V Vishnu Prasanna (India) 6.5 lost to Mikheil Mchedlishvili (Georgia) 6.5, K Rathnakaran (India) 6.5 beat Dipatyan Ghosh (India) 6.5 Final standings: 1. Abhijeet Gupta 8.5 points, 2. Aleksej Aleksandrov 8, 3. Pavel Ponkratov 8, Levan Pantsulaia (Georgia) 8, 5. M Pranesh (India) 8, 6. Nodirbek Yakubboev (Uzbekistan) 7.5, 7. Mikheil Mchedilshvili (Georgia) 7.5, 8. Alexei Fedorov (Belarus) 7.5, 9. C R G Krishna (India) 7.5, 10. Debashis Das (India) 7.5.