The top-five finish, his seventh of the season, sees him jump ahead of US Open winner Matthew Fitzpatrick into second on the DP World Tour standings behind world number two Rory McIlroy.
Overnight co-leader Paul had been in the driving seat on the back nine before a two-shot swing at the 15th handed his playing partner Marcus Armitage a two-shot lead with three holes to play.
But as Armitage dropped three shots over the next two holes, Paul saved par at the 17th to find himself tied as he made his way to the 18th.
The German then coolly slotted in a difficult 15-foot birdie try from the fringe at the last to deny Paul Waring and Nicolai von Dellingshausen a play-off.
Fox earned €94,526.96 ($NZ162,000) for the fourth placing taking him to €2.6m (NZ$4.5m) for the year with two events to play - the Nedbank Golf Challenge in South Africa next month followed by the DP World Tour Championship in Dubai.