This is the second consecutive victory on the European Tour for Singh. He defeated Padraig Harrington in a playoff last week at the Malaysian Open. It is the ninth time that Singh visited the winner's circle on the European Tour.
'Over the past two weeks the key has been consistency,' Singh said of his recent strong form. 'I didn't make too many mistakes. I haven't played in Malaysia and Singapore since 1993 and it has been a good homecoming.'
Singh came into Sunday's final round with a one-shot lead over Frankie Minoza but that lead was extended right out of the gate with a birdie at No. 1.
The lead was pushed further thanks to a bogey by Minoza at the second. Singh carded a birdie at the fourth and that gave the reigning Masters Tournament champion a three-shot advantage over Bennett and Mikael Lundberg.
Singh cruised along until two mid-round bogeys. He bogeyed the 7th hole for the second straight day, but Bennett and Lundberg also dropped a stroke to preserve Singh's three-shot lead. Anders Hansen shot up the leaderboard at this point and when Singh bogeyed No. 8 and Hansen birdied the 11th, the lead shrunk to one.
Singh rebounded at the 9th with a birdie-3, his fourth birdie at this hole during the week. He parred the next three holes to keep his two-shot edge before he birdied the 13th to go back up by three.
A birdie at the 15th extended Singh's lead to four and that was enough to withstand the late run by Bennett.
The win marks the 30th professional victory for Singh, who turned 38 on Thursday.
'Before I came over here to Asia to play, I said to my wife that it would be nice to win both tournaments, so I managed to do that,' Singh said.
'Every time I tee up, I am always thinking I am going to win. Even if I don't win I guess it is my expectations to win a golf tournament. This time I guess it came true.
Bennett earned his highest finish in a European Tour event since he captured the Scottish PGA Championship in 1999. He chipped in for eagle at the 18th hole to finish with a final round 68 and vault ahead of Maarten Lafeber and Colin Montgomerie, who ended the tournament at 18-under.
Lafeber scored four back nine birdies on Sunday to shoot a 65 and share third with Montgomerie.
Monty, who won in Australia last week, carded two early bogeys but rebounded with five birdies over the remainder of his round for a 3-under 68.
'I got off to a bad start,' he said. 'I started bogey-bogey. I had only had one bogey the first three days and then started bogey- bogey. I got it back at the fifth and sixth but it was always a struggle. I didn't play well today.'
Hansen and Harrington tied for fifth at 17-under, while Lundberg and Minoza were a shot back at 16-under 268.
Prayad Marksaeng finished alone in ninth at 15-under and Clay Devers rounded out the top-10 at minus 14.
Click here for Full-Field scores from the Singapore Masters!