Unseeded Stefan Koubek of Austria cashed in on his rival's wrist injury and put paid to the aspirations of seventh seed Paradorn Srichaphan to move in to the quarterfinals of the ATP Tour Chennai Open Tennis championship on Thursday. Not to discount the deserving win, the Austrian nicknamed 'Cooley' did not labour much to wrap up a 6-1 6-2 win in just 47 minutes and will play the winner of the match between Igor Andreev (Russia) and Santiago Girlado (Colombia) in the quarterfinals. In another match on the side courts, sixth seed Fabrice Santoro of France eliminated Bjorn Phau (Germany) 6-4, 6-2. Santoro, who had withdrawn from doubles due to back problem on Wednesday, had a slight edge over his rival and excelled himself from net play for winners. Santoro will play third seed Xavier Malisse of Belgium tomorrow. Koubek, who had reached the ATP Doha Open Final last year for his career best showing besides beating Roger Federer in 2001, said he was aiming to break into top 50 this year. "Srichaphan had a wrist injury but I played very well. Everything was going right for me. My goal for 2007 is to move to top 50 in ranking," he said at the post match press conference. On the other hand, Srichaphan, a winner here in 2003, said "the wrist tendon is not that serious and I could not push myself harder. I have had this problem for a while and I had to withdraw from singles play in the Doha Asiad too. "I will surely go out for my doubles match today partnering compatriot Ratiwatana Sonchat against Rafael Nadal and Bartolome Salva Vidal (Spain)," he said. Srichapan added that he would not skip the Australian Open.