Haas came away a 6-3, 4-6, 6-4 victor over Haase to win the tournament in Vienna for a second time. The first was in 2001. He is 15-12 overall in ATP title matches since reaching the finals of Lyon, France, in October 1997. His 15 career titles are ninth-most among active players.
Haas, who also won the championship Munich in May, has an outside chance of qualifying for the ATP World Tour Finals with two tournaments remaining.
Haas ended up with five breaks Sunday against Haase, with two in each the first and third sets. Haase, with four breaks and at least one in each set, kept things close and Haas won only five more points -- 100-95 -- over the course of the match.
Haas earned about $124,000 along with the title and has career winning of about $12.5 million. Haase, who fell to 2-2 on tournament finals, picked up more than $65,000 Sunday. He's won more than $2.4 million in his career.