Up against Otto Virtanen, ranked as low as 419 in the ATP ranking chart, the 165th ranked Prajnesh lost 3-6 6-7(1) in just one hour 25 minutes.
Indian tennis pair Ramkumar Ramanathan and N Sriram Balaji lifted men's doubles event at the Cassis Open Provence in France.
Nagal had played in the Australian Open main draw early this year and had lost in the first round and he could not qualify for the French Open and missed the Wimbledon qualifiers.
Indian faceoff at Wimbledon: Sania Mirza, Rohan Bopanna to lock horns with Ankita Raina, Ramkumar Ramanathan in first round
Earlier in the day, Sania and her doubles partner Mattek-Sands sailed into the second round of the ongoing Wimbledon Championships.
Ramkumar Ramanathan today improved his career-best rank to 168 in singles, while Sania Mirza was unchanged at number seven in the doubles.
Ramkumar, coming into Antalya Open, had won a total of three matches at that level, with his last coming in Chennai in 2016.