The 32-year-old had blown his four-shot advantage going into the final
round, carding a two-over par 74 and leading to a three-way play-off with Peter Lawrie and Gary Boyd.
But he held his nerve to sink an 18-foot birdie putt on the second play-off hole as Irishman Peter Lawrie and England's Gary Boyd both made par.
It was his second victory on the European Tour this year following his success in Mallorca which also came by virtue of a play-off, on that occasion beating home favourite Alejandro Canizares.
The win saw Hanson move into the automatic qualifying spots for the Ryder Cup leaving veteran Ryder Cup player Miguel-Angel Jiminez of Spain in the ninth and final spot.
The Swede's victory dropped England's Paul Casey out of the automatic places with just one qualifying event remaining, next week's Johnnie Walker Championship at Gleneagles.
Casey has chosen not to play the event and must now rely on one of captain Colin Mongomerie's three wild card picks - although with Padraig Harrington, Luke Donald and Justin Rose in a similar position there is no guarantee he will get it.
Jimenez - who shot a final round 73 - too is missing the Gleaneagles tournament as the bon vivant - who is renowned for his liking of fine wine and cigars - is attending his nephew's wedding.
The 46-year-old three time Ryder Cup player could lose out on an automatic place for the biennial match with the United States should either Simon Dyson, Ross McGowan or Alvaro Quiros win the trophy.
Hanson said it was the culmination of a terrific week's work with mission accomplished and was setting his sights on the Ryder Cup which takes place at
Celtic Manor near Newport in Wales from October 1-3.
"To make that putt (the winning one in the play-off) feels fantastic," said Hanson, who has won all three of his EPGA play-offs.
"And to know I had to come here and win (to move into the Ryder Cup spots) and pull it off feels great.
"There's another week to go but it looks and feels a whole lot better."
Dyson made his chances of qualifying for the team for the first time more difficult as he carded a 72 to finish two shots off the pace.