The Australian shot 70 in the final round to tie Remesy at 16-under 268. Remesy shot 64.
'I am in the best form of my life now,' the 36-year-old Green said.
Chris Gane, Miguel Angel Jiminez and Michael Jonzon shared third at one stroke behind.
This was Green's second European Tour title, coming 10 years after he won the 1997 Dubai Desert Classic in a playoff with Ian Woosnam and Greg Norman.
'It's hard to tell why it took so long to win again,' Green said.
'I didn't want to put any undue pressure on me after taking the lead Friday. For sure, I have more self-belief now than I had ever before.'
Green led the BA-CA Open from the second day. He started the final round at 15-under 198 and briefly lost the lead to Jiminez after double-bogeying the par-4 third.
Jiminez had four birdies and an eagle on the par-4 fifth, but bogeying the eighth and 12th holes was costly.
'I felt like winning the tournament after that eagle on the fifth,' Jiminez said. 'But my concentration slipped away a bit after being disturbed by some photographers.'
Green recovered with four birdies and looked set for victory, but bogeyed the par-5 18th to let Remesy back in with a chance.
Play was interrupted for more than two hours because of rain and lightning.