Wilson, having missed the cut in half of the previous eight tournaments in which he has appeared in 2012, stood at 13-under 131 after two rounds at the Santo de Serra Golf Club.
Magnus A. Carlsson, Joakim Lagergren and Andy Sullivan shared second place at 133 while Sihwan Kim was alone in fifth at 134.
Wilson, a member of the European Ryder Cup team four years ago, has nine runner-up finishes on the European Tour without a victory.
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