Wawrinka, the top-seed Swiss, outlasted Italy's Potito Starace 6-4, 3-6, 6-4 in one semifinal while third-seeded Hanescu of Romania breezed past Florent Serra of France 6-4, 6-1 in the day's other match.
Sunday's final will mark the eighth career ATP singles final for Wawrinka and second this year -- the world No. 23 was defeated in January's Chennai Open by Marin Cilic. He holds an anemic 1-6 record in title matches.
Hanescu likewise has only one ATP singles title and before the Casablanca event had not gotten past the second round in any of his first six 2010 tournaments. But he has beaten Wawrinka both times he has faced the Swiss.