The 31-year-old Dane shot 7-under 65 on a blustery Friday at the Wentworth Club to move to 11-under-par 133, two strokes clear of three-time champion Colin Montgomerie and Eduardo Romero.
Montgomerie followed his course-record tying 64 with a 1-under 71. Romero shot 68 to get to minus 9.
Montgomerie shrugged off constant back pain in taking the first-round lead. Friday, it was his finish, not his back that produced pain.
Flawless through his first 14 holes, and leading the tournament at 12-under, Montgomerie missed a five-foot par putt at the 15th. He then hit his tee shot at the par-4 16th into the right gallery. His ball caromed off the skull of a spectator and further right into the base of some brush. An ambulance came to care for the patron, Jonathan Edom, but could do nothing for Montgomeries poor lie. He was forced to take a drop and dropped another shot.
Guy Kinnings, Montgomeries manager, said: Colin was visibly shaken by the incident and enquired about Mr. Edoms health after finishing his round. We have his phone number and Colin will be contacting him.
With a pair of par-5s to finish, Colin had ample opportunity to right the ship before signing his card. Yet, he missed another five-footer for birdie at the 17th, and failed to save par from inside three feet at 18.
While Montgomerie has won 26 times on the European Tour, including this event from 1998-2000, Hansen is still in search of win No. 1. He finished tied for third three weeks ago in the French Open, and tied for ninth last week in Germany.
I have been playing well in recent weeks and it just feels like it is keeping on happening for me, he said. I dont know why particularly, but it has been a long time coming. I really worked hard on my game for a long, long time and it seems like its paying off. Im starting to get a bit more confidence and the more confidence I get, the easier it gets.
Hansen recorded eight birdies and one bogey in the second round.
Obviously it is not easy to win a tournament out here, Hansen said. There are so many great players out here and this week is probably all the best players in Europe. You have guys like Monty playing really well so its going to be very, very tough.
Full-field scores from the Volvo PGA Championship