( CNN ) -- Argentina 's Juan Martin Del Potro made a disappointing comeback from injury at the Thailand Open in Bangkok on Tuesday , where he was defeated 7-6 6-4 by Olivier Rochus of Belgium in the opening round . The 22-year-old has not played on the ATP Tour since losing in the fourth round of the Australian Open in January , after sustaining a wrist injury which has seen the former world number four slip to 36 in the world rankings . But despite serving 16 aces during the match , the 2009 U.S. Open champion 's return to the game was cut short by world number 78 Rochus in just under two hours . A foot shorter than his two-meter , Rochus came through a close first set and a break down in the second to book his place in the second round of south-east Asian tournament where he will play Kazakhstani Mikhail Kukushkin . After the match fifth seed Del Potro was full of praise for his victor and said he was just happy to be playing again despite the loss . `` I played a good match , '' Del Potro told the official ATP website . `` I had my chances in the first-set tie-break and he played some great points . He served very good , which was important on this kind of surface . He played very well today . `` I 'm just happy to be back on the circuit and I hope I get better and better . '' The result opens up the draw for world number one Rafael Nadal , who would have faced Del Potro in the quarterfinal . The Spaniard will be playing in the tournament for the first time , after arriving in the Thai capital on Tuesday . The newly crowned U.S. Open champion will face Belgian qualifier Ruben Bemelmans in a second round match on Wednesday . Meanwhile in Tuesday 's other first round matches , Germany 's Rainer Schuttler defeated Brazil 's Ricardo Mello , Guillermo Garcia-Lopez of Spain beat German Michael Berrer , and world number 13 Jarkko Nieminen saw off home favorite Danai Udomchoke .
Juan Martin Del Potro loses on comeback to tennis after wrist injury . Argentine ace was playing first match since Australian Open in January . Belgium 's Olivier Rochus beats Del Potro in straight sets in Thailand . World number one Rafael Nadal wins his third title of the year and eighth overall at Indian Wells.