Singh posted an even-par 71 to complete the rain shortened event at 15-under- par 198.
This was Singh's third tour win after he was victorious twice in the '06 season.
'Win or get a W under you belt is what we play golf for I think,' Singh said. 'The more you have the better it is for a golfer and more satisfied he feels and more confidence he gets, that is what I am getting out of this. I am very fortunate that it happened to me today with 18 pars.'
The event was shortened after heavy rain completely washed out Thursday's play. There was also bad weather forecast for Sunday, but play was completed before the storm struck.
While Singh was running off 18 consecutive pars, he was never seriously threatened. Several players got to minus-13, but it wasn't until the final hole that someone pulled within one of his lead.
Simon Wakefield ran off three birdies over the final four holes to shoot 3-under 68 and finish one shot back at 14-under-par 199.
'After the front nine, I was just trying to hold on to my position,' Wakefield admitted. 'After the turn, I felt quite comfortable. I got a little more aggressive and it paid off.'
Iain Pyman (65), Martin Erlandsson (65), Pelle Edberg (65), Peter Fowler (69) and Michael Jonzon (67) shared third place at minus-12.
Singh, who shared the lead after the opening round and was the sole leader after round two, did struggle during the middle of the final round.
He three-putted for par on the par-5 ninth and was lucky to escape with pars at 10 and 11. At the 10th, Singh was nearly 90 feet from the hole, but calmly two-putted for par.
Singh again hit a poor approach on 11 at Fontana Golf Club. He was more than 60 feet from the cup, but again managed a two-putt par. Singh got up and down from over the green at the 13th.
Singh wasn't the first player to fire a perfect round and win. Nick Faldo parred all 18 holes en route to his first British Open title in 1987.
Soren Hansen, one of a few players slated to compete next week in the U.S. Open, closed with a 2-under 69. He was joined in a share of eighth place at 11-under-par 202 by Francois Delamontagne (65), Graeme McDowell (68), Sam Little (67) and Robert Rock (65).