Aguilar, a Chilean, beat India's Jeev Milkha Singh by a single shot at 18-under 262, recovering from a bogey at the 15th with his closing birdie at 18.
Singh carded a 3-under 67 in the final round, making costly bogeys at the 16th and 18th holes after posting two eagles and a birdie earlier in the day. He finished alone in second place at 17-under 263.
Aguilar and Singh played in the final threesome together. The two-shot swing on the 18th hole -- Aguilar's birdie and Singh's bogey -- gave the Chilean the win.
Singh -- who trailed Aguilar by two shots overnight, but led by one after 17 holes on Sunday -- missed a 4-foot putt at the 18th that would have sent the tournament into a playoff.
'It was Aguilar's day and not mine today,' said Singh. 'It was disappointing for me but I guess that's golf. Aguilar deserves this win and I congratulate him.'
Aguilar had fallen two shots back after a three-putt bogey at the 15th, but Singh did him a favor by making bogey at the 16th, trimming his advantage to just a shot.
Feeling like his round was falling apart after 15 holes, Aguilar became more aggressive with his putts down the stretch.
'After he made bogey on the 16th I realized that I was still in the game,' said Aguilar. 'I knew I had to make a three on the 18th for a playoff. I said he needs to make three if he wants to beat me. I was so sure that I was going to birdie. I didn't expect him to bogey, but you never know how golf is. It's not over till it's over.'
Aguilar was a two-time winner on the European Challenge Tour. Prior to this week, he had participated in only one European Tour event this season, missing the cut at last week's Indian Masters.
'It feels awesome to win,' he said. 'This is one of things that I wanted to do when I decided to start playing golf again and come back out on tour. I won twice on the Challenge Tour last year and I felt I had the game and that I was playing well -- I just had to hope that it would be my week and it turned out to be my week.
'This is life changing for me. I can play whatever I want to play and can play easily. Hopefully there is more of this to come.'
South Africa's James Kamte and Thailand's Prom Meesawat both shot 67 to share third place at 16-under 264. New Zealand's Mark Brown and Joost Luiten of the Netherlands posted matching 66s to end another shot further back at 265.