The 31-year-old duplicated the feat of Yevgeny Kafelnikov in 1995 as he improved to a perfect 5-0 record over Haas, the ATP No. 57.
The 65-minute final played in bright sunshine, which has characterized the summer clay week in the Alpine village at 800m, marked the first trophy for Youzhny since 18 months ago in Zagreb. He won his last on clay more than three years ago in Munich.
Despite hailing from the flatlands of the Netherlands, Haase has made his best results in similar conditions to Gstaad, winning the last two editions of the tournament in the Austrian ski resort of Kitzbuehel. He is traveling there to begin his title defense this week.
Youzhny broke once per set, for 5-3 and the first and early in the second. However, he had to recover from 0-30 down as he served for victory, requiring three match points to get the job done.
The Russian lost a final last month in Halle on grass to Roger Federer, who along with compatriot and No. 10 Stanislas Wawrinka had been billed as the anchors of the event.
AP, UMAG, Croatia
Tommy Robredo won the Croatia Open on Sunday, beating Fabio Fognini of Italy 6-0, 6-3 for his 12th career title and second this year.
The Spaniard won the opening set in only 18 minutes, losing just six points with Fognini helpless to reverse the rout from the clay-court baseline. Fognini broke Robredo twice in the second set, but could only hold serve once himself.
Robredo also won on clay at the Grand Prix Hassan II in April in Casablanca, Morocco. Eleven of his 12 titles have been on the surface.
The result halted an impressive run by Fognini. The Italian captured two titles in winning 13 straight matches en route to the Umag final. He won both tournaments in Germany, in Stuttgart two weeks ago and Hamburg on Aug. 21.