The 41-year-old Scottish veteran posted a final round 71 to end at 16-under-par for the tournament, one stroke better than long-hitting Angel Cabrera (68) and two in front of four-time Volvo PGA champion Nick Faldo (67).
Prior to this week, Oldcorn ' a two-time winner on the European tour ' had not tasted victory since the 95 DHL Jersey Open, and in the last few years had begun to doubt his abilities.
Yet, all week, he displayed the kind of golf that is required of winning at Wentworth, and the victory came as the most pleasant of surprises for him.
It may sound a bit nave or corny, said Oldcorn, but this was the one championship that I always wanted to win on this tour. I first played on this golf course when I was 14 and I just fell in love with it immediately.
Oldcorn comments on his win at the Volvo PGA
That love was apparent over the first few days, as Oldcorn opened a record-setting five-shot lead over the field through 54 holes.
On Monday, however, he struggled early, making two bogies through his first nine holes and opening the door for Faldo and Michael Campbell (70), who got to within two shots of his lead.
I struggled over the front nine, and then I saw Nick was storming up the board and Michael was getting closer, but it actually made me play better, Oldcorn claimed. It changed my focus and I played really good on the back nine.
It must have indeed changed his mental take, as he went on to make a quick birdie at the par-5 12th to get back to minus-14.
Meanwhile, Campbell faltered with two late bogies in his round to fall back and end in a tie for fourth at 11-under, while Faldo was unable to birdie the finishing par-5 18th to tie the score.
In the end, it was Cabrera who put on a late charge, posting an eagle at No. 12, a birdie at the 17th, and yet another eagle on No. 18 to get within a single stroke at 14-under.
Oldcorn responded, however, with a birdie of his own at the 17th and then another from six feet on the last to seal the deal in style.
I wasnt nervous, he stated proudly. I was really quite composed. And that makes me more happy than anything.
Full-field scores from the Volvo PGA Championship