'This is fantastic. When I was injured (several years ago), I didn't know if I was going to come back in the sport,' said Singh. 'When I came back, I wasn't thinking the same way. I was putting pressure on myself and I was getting down. I started working hard and the wrist became better and things started looking better for me. I've just won and it's one of the best feelings.'
Gonzalo Fernandez-Castano, who won the KLM Open last year, also carded a 70 in the final round to take second place at 9-under-par 279.
Second- and third-round leader David Lynn failed to hold the lead in the final round for the fourth time in his career. Lynn stumbled to a 1-over 73 to end alone in third place at minus-8.
Paul Casey, who won this crown in November, shot 72 in the final round and shared fourth place at 7-under-par 281 with Peter Fowler (71), Jarrod Lyle (70) and Simon Wakefield (71).
Singh, who played alongside Lynn in the final round, opened with a bogey on the first at Honghua International Golf Club to fall two behind his playing partner. Singh atoned for that early mistake with a birdie on the third to get back to minus-eight.
The 34-year-old was tied for the lead at that moment with Lynn, who had bogeyed the third. However, Lynn bounced back strong with birdies on four and five to move to 10 under.
Singh remained within one as he matched Lynn's birdie on the fifth. The India native again grabbed a piece of the lead as he birdied the seventh to join Lynn at 10 under.
Lynn fell one behind as he bogeyed the ninth, but came right back with a 10- foot birdie putt on 10 to regain a share of the lead. The 32-year-old dropped a shot back with a three-putt bogey on the 13th and he would not recover.
Singh birdied No. 14 to gain a two-stroke cushion on the field. He parred his next three holes. Singh faltered to a three-putt bogey at the last, but it was good enough for his first European Tour crown. Singh joined Arjun Atwal as the only two players from India to win on tour.
Lynn dropped three behind Singh with another three-putt bogey on the 15th before parring his final three holes. Lynn has led entering the final round four times in his European Tour career and ended up finishing third, fourth, fifth and third respectively in those events.
'I want to try and win more tournaments, so I feel like I have let this one slip a little bit to be honest,' said Lynn. 'But it is still a good finish, I have to take the positives out of it. It is another top-three finish.'
Fernandez-Castano, who was the rookie of the year in 2005, played the front nine in minus-1 with a birdie on the fifth that got him to minus-8.
The Spaniard moved to 9 under with a birdie on the 10th. Fernandez-Castano got within one of Singh's lead as he birdied 17. However, he drove into the woods at the last and stumbled to a bogey to end one shy of a possible playoff.
'I had a good number of birdie chances and it was a shame because my putting was okay, but not enough went in,' said the Spaniard. 'It was a shame about the drive on the 18th which cost me a bogey. It is a difficult hole to par to win a tournament and I would have liked to have parred it to put a little bit of pressure on Singh.'
Peter O'Malley (68) and Ter-Chang Wang (70) shared eighth place at 6-under- par 282.
Paul Lawrie, who was one of five players to shoot in the 60s Sunday, fired a 5-under 67 to end at minus-5. That was the low round of the day. He was joined in 10th place by Simon Dyson, Peter Hanson and Prayad Marksaeng.