There was no hesitation from the 40th-ranked Pospisil, from Vernon, B.C., who admitted that he cut back on his training sessions over the last few days to conserve energy as the long ATP season finishes next week at the Paris Masters.
Haase, who reached the final against Tommy Haas in Vienna, put Pospisil out in the Vienna second round. of that tournament. But that result counted for nothing in the Swiss showdown.
Pospisil played steady, controlled tennis at the St Jakobshalle, breaking Haase once per set to get the job done in just under 90 minutes and gain a measure of self-satisfaction.
"I've had to conserve energy, it's the end of a long season," said Pospisil, who lost in opening singles in Basel alongside Toronto's Daniel Nestor. "I've cut (practice) back just a bit since last week.
"I'm feeling the effects of a lot of tennis, so I didn't train quite as much. I had to return well against him, I wanted to win it after losing to him. He was full of confidence after Vienna, so I had to play well. I'm pretty pleased with the entire effort, happy with how I played."
Pospisil, who is hoping to lift his ranking by at least eight spots in hopes of getting a seeding at the Australian Open in January, broke Haase in the final game of the first set and again in the last game of the match, advancing on his first match point.
He beat Haase with a modest three aces and never dropped serve, putting the Dutchman under pressure with 11 break points.
Pospisil next faces the huge serve of Ivo Karlovic, who stunned second seed Tomas Berdych in the opening round. The Croatian beat Pospisil in their only previous meeting on grass in Newport the week after Wimbledon.
"I go in with nothing to lose," Pospisil said. "He's got probably the biggest serve in the history of the game and I'll certainly have to return well."Suggest a correction