Hanson could become the third straight Swede to win a European Tour tournament in Sunday's fourth round.
Countrymen Alexander Noren (European Masters) and Peter Hedblom (Johnnie Walker Championship) won the previous two events.
"When I stood on the first tee here this week, I decided I wanted to get into contention again," Hanson told reporters.
His bogey-less third round included five birdies, four on the front nine.
Hanson's total, 11-under 205, leads the trio of England's Simon Dyson (68), Denmark's Soren Hansen (70) and South Africa's James Kingston (70).
All three are at 10-under 206, tied for second place.
Another Swede, 2008 winner Robert Karlsson, did not return this year to defend his title because of an eye ailment.