Wilson, who has a habit of finishing second, shot a 5-under 65 for a three-round total of 13-under 197, a shot better than Taiwan's Lin Wen-tang (64). Langer had a 63 and was two back of the leader.
John Daly, the troubled two-time major winner, struggled after two solid rounds, shooting a 73 and falling 12 back of Wilson.
The 51-year-old Langer, a two-time Masters champion, hasn't won on the European tour since 2002. He recovered from a bogey at the first hole by making an eagle and seven birdies. The eagle and one of the birdies came on 7-iron shots from the bunker.
"It was kind of a very strange day," Langer said, adding he wasn't surprised to be on the leaderboard because he's won four times on the senior circuit this year.
Langer, whose 18-year-old son Stefan is caddying for him this week, said he prefers the shorter course at the 6,128-meter Hong Kong Golf Club because it relies less on power, echoing comments made by another veteran in the field, Colin Montgomerie, on Friday.
"I'm not a long hitter, so it's more about precision and being straight and maneuvering the ball a little bit. You have to hit a few cuts and a few draws, and that's kind of my game," said Langer, who won this event in 1991.
"I just can't hit the ball as far as the youngsters ... Doesn't matter what I do," he said.
Seeking his first win on the European tour after eight second-place finishes, Wilson was the only player among the four co-leaders after the second round to stay ahead.
"Like I keep saying, if I can keep getting up there, I'll break through eventually," Wilson said.
Eight-time European tour Order of Merit winner Montgomerie also played solidly, recovering from a double bogey on the first to shoot a 70. He sits in eighth place, one shot behind Spain's Pablo Larrazabal (64), Northern Ireland youngster Rory McIlroy (66), Italy's Francesco Molinari (67) and India's Jeev Milkha Singh (66) at 10-under.
Miguel Angel Jimenez's chances of defending his title were diminished after the world's No. 20-ranked player made a double bogey and two bogeys to finish with a 71 for the round. He is 14 strokes behind Wilson.
Louis Oosthuizen and Oliver Fisher both had 73s to lose their share of the lead after two rounds, while Chawalit Plaphol struggled on the greens for a 70 to fall five strokes off the pace.