Montgomerie shared top honors last week with Bernhard Langer at the Volvo Masters Andalucia but the talented Scotsman never visited the winner's circle in Asia until Sunday.
'It shows to my peers that I'm still there, that I've not gone away and I'm still competitive at the highest level,' said the former seven-time European Tour Order of Merit champion. 'It's nice to show that. I was very tired coming over here from Spain. To get to China is not the easiest route and all credit to my caddie and I to last out.'
Thongchai Jaidee, the overnight leader, finished alone in second at 14-under par.
Montgomerie took the lead in the tournament for the first time with a 25-foot birdie at the eighth. He added to his lead with a birdie at No. 10 but Jaidee would strike back.
Jaidee, last year's Asian PGA Tour Order of Merit champion, drew even with birdies at 14 and 15 but ran into trouble at the next hole. He struck a poor approach that left him with a tricky 40-footer, and the 33-year-old three-putted for bogey.
Both players birdied the 17th but Jaidee's chances were dashed when he pushed his approach at 18 and bogeyed the hole.
'I really enjoyed playing with Colin (Montgomerie),' said Jaidee, who moved to first on the Asian PGA Tour money list. 'It was a great experience, so I am not too disappointed.'
Jaidee shot a 1-under 71 on Sunday.
Montgomerie won tournaments in consecutive weeks for the first time since 1994 when he took the English and German Opens.