VIENNA, Austria -- Canadian Daniel Nestor suffered disappointment in only his third doubles final of the season as he and first-time partner Julian Knowle of Austria lost 7-5, 6-4 to Romanian Florin Mergea and Czech Lukas Rosol at the Erste Bank Open on Sunday.
The defeat added more misery to what has been a dismal season by the Toronto product's world-class standards. The 41-year-old teamed with Knowle, a 2007 U.S. Open doubles winner, after Austrian Jurgen Melzer had to withdraw with a shoulder injury.
Third seeds Nestor and Knowle let a 5-2 lead slip in the first set and were unable to recover as their opponents built momentum to conclude the upset win.
"I came here not ever sure of playing doubles this week," said Nestor. "Asia was a frustrating trip, we (Nestor and Leander Paes) had two matches where we were up match points in Beijing and Shanghai and we lost them both.
"Out team today also had chances but we couldn't convert them."
Nestor and Paes won the Winston-Salem title the week before the U.S. Open, the Canadian's only trophy success in 2013. He and former regular partner Robert Lindstedt of Sweden reached the spring Barcelona final.
Nestor will miss the year-end World Tour Finals in London for the first time since it moved to Britain from Shanghai in 2009.
In the men's single's final, Tommy Haas won his 15th career title and second of the season by defeating Robin Haase of the Netherlands 6-3, 4-6, 6-4 at the Erste Bank Open on Sunday.
The second-seeded German, won also won the event 12 years ago, maintained his slim chance of qualifying for next month's ATP finals in London.
"This victory is really something special," the 12th-ranked Haas said. "You don't win tournaments too often and this year I've won in my two favourite cities."
The 35-year-old Haas had already become the oldest tournament winner of the season by taking the title in Munich in May.
Haas, who improved to 15-12 in career finals, said he was "very proud" of what he achieved after recovering from hip surgery in 2010.
"If you'd seen me 3 1/2 years ago ... I was really asking myself if it made sense to continue," Haas said. "I have been paying a lot of attention to my fitness and nutrition and I am always looking to improve my tennis."
Haas came back from a break down to win the opening set and appeared in control when he broke Haase again and led 1-0, 40-15 in the second set. However, Haase won that game and broke Haas again at 5-4 when the 63rd-ranked Dutchman converted his first set point with a lob.
Haase had another break to go 4-2 up in the decider but immediately dropped his serve on a double fault and failed to win a game afterward. Haas closed out the victory on his first match point when Haase sent a backhand long.
"I am disappointed as I've had my chances," said Haase, who upset top-seeded Jo-Wilfried Tsonga in the semifinal. "When I broke him at 1-0 in the second set, I started to feel stronger. I believed I could turn around the match. But he played all or nothing at the end and that paid off for him."
It was Haase's second defeat in a final this year after losing in Gstaad, Switzerland, three months ago. The Dutchman won both his career titles in Austria -- on clay in Kitzbuehel in 2011 and '12.