With this win, Wawrinka improved his head to head record against Haase to 5-0, having also beaten him in this year’s Estoril quarterfinals.
The Swiss, who lost to Djokovic at last week’s Madrid Open, will play 8th seeded Serbian Janko Tipsarevic next, who has a first round bye.
Also through to the next round is Radek Stepanek of Czech Republic, who came back from a set down to beat the Argentine Juan Ignacio Chela 2-6 6-0 6-3.
Next up for Stepanek will be the winner of the match between the Romanian qualifier Adrian Ungur and 14th seeded Argentine Juan Monaco.
In the other first round matches, Australia’s Bernard Tomic ousted Colombian qualifier Santiago Giraldo in three sets 4-6 6-2 6-4, Andreas Seppi of Italy defeated Denis Istomin of Uzbekistan 6-4 3-6 6-3 and another Argentine Carlos Berlocq booked his place in round 2 by beating Slovenian qualifier Blaz Kavcic 6-1 6-3.