The 15-year-old native of Austria, who was a qualifier, beat No. 6 seed Maria Elena Camerin of Italy, 7-5, 6-1.
It was the first title for Paszek, as Camerin failed in the quest for her first crown.
"The first set was quite important; she was up 5-4 and had set points on my serve," Paszek said. "But I held and won the set which was important for me and I got more confidence. It's a perfect ending for me."
At 15 years, nine months and 18 days, Paszek is the youngest player to win a title this year -- beating a 17-year-old Michaella Krajicek of Netherlands -- and the seventh-youngest in history.
Camerin has never won a WTA event. This was her second career final, as she also lost at Casablanca in 2001.