England's Steve Webster posted a 67 to finish one shot off the lead alone in third place at 8-under-par 208. Defending champion Trevor Immelman followed at 7-under-par 209 along with Raphael Jacquelin.
Hansen began the day in a tie for sixth at Erinvale Golf & Country Club but used a quick start to make a charge.
The Dane picked up his first birdie of the day at the par-3 second and followed that up with an eagle at the par-5 third. Hansen then birdied the par-4 fifth to reach 9 under.
Hansen added a birdie at the 13th and took the outright lead at minus 11 with a birdie at the par-4 15th.
The 33-year-old found trouble at the par-5 16th and double-bogeyed the hole under windy conditions. At the end of the day, however, Hansen's early success was enough to give him a share of the lead heading into the final round.
'I have enjoyed this week which is great,' said Hansen, who is seeking his first victory since his breakthrough at the 2002 Volvo PGA Championship. 'My scoring has been good and it has been a good start to the year for me.'
Lile, who was one of three overnight leaders, stumbled out of the gate with a bogey at the opening hole but ran off four consecutive birdies starting at the par-5 third to move to 10 under.
The South African cooled down from the point on and bogeyed the 16th to join Hansen in a tie for the 54-hole lead.
'The more times you get into a position like this, the easier it becomes,' said Lile, who carded a 70 in the third round. 'Golf is golf whether you are playing a big tournament or a small tournament. I don't know what is going to happen tomorrow, I can't control other people, but we will see what happens.'
Immelman, who earned his first career victory on the European Tour at this event last year, bogeyed the first but responded with an eagle at the third.
The 24-year-old then birdied the fifth before catching fire on the inward nine.
Immelman birdied the par-4 10th and picked up the first of three consecutive birdies at the par-3 12th to move into contention at 10-under par.
The South African, who is trying to become the first person since Gary Player to win this event in back-to-back years, fell apart down the stretch, however, with bogeys on each of his last three holes to finish two shots off the pace.
'If I can be two behind going into every final round this season it is going to be a fantastic year,' said Immelman. 'It is my first week of the year. I am going to make a few mistakes but hopefully I am not going to make them tomorrow.'
Stephen Dodd of Wales finished alone in sixth place at 6-under-par 210. Alastair Forsyth, who held a share of the 36-hole lead with Lile and Nico Van Rensburg, was one shot further back along with first-round leader Brett Rumford and Darren Fichardt at 5-under-par 211.
Van Rensburg followed at 4-under-par 212. He was joined by Charl Schwartzel, Marcus Fraser and Nic Henning in a tie for 10th.