BANGKOK (AFP) - Philipp Petzschner sprang the first upset of the Thailand Open with a 6-4, 7-6 (7/4) defeat of error-prone Russian Marat Safin on Tuesday. The world-ranked 131 German reached the second round at the ATP level for the fourth time this season as he caught a frustrated Safin flat-footed to deny the former number 1 his 400th career match win. The Russian seventh seed struck 33 unforced errors while his underdog opponent fired a dozen aces and 13 winners in one hour, 41 minutes. "I didn't feel comfortable on the court, it's just the way I was today," said a deflated Safin, a semi-finalist in his previous two appearances. "I didn't play well, nothing happened for me out there. It's my job to play tennis and I didn't do it well today." Swede Robin Soderling played his first match in nearly a month, defeating Aisam-Ul-Haq Qureshi 6-2, 6-4. Soderling, ranked 34th in the world, fired 15 aces to seal the victory. "The first round is always tougher than almost any other match - save the final," said the 24-year-old Swede, who suffered opening round losses at both the Beijing Olympics and the US Open. "But it felt good to get back on court. I feel really refreshed and ready for the indoor season." Soderling said Qureshi, ranked 207th in the world and the only Pakistani player of note on the ATP tour, had "served well and was tough on this medium-fast surface." "He played a lot better than I would have expected," added the Swede, who moved to 33-17 this season. Soderling, who converted three of eight break chances, is hoping to revitalise a 2008 campaign which began with promise after consecutive runner-up finishes at Rotterdam and Memphis in February. The Swede said he took a week to mull his loss to Russia's Evgueni Korolov in the first round at Flushing Meadows, but now felt revitalised. "I just took a break, I really just rested for a week. Now I'm relaxed and ready to play again," he told reporters. World number 3 Novak Djokovic, who heads the field in Bangkok, has a bye into the second round. The 21-year-old Serb last played here in 2004 on a wild card, losing in the first round. If he gets through to the final, he could face second seed Jo-Wilfried Tsonga of France in what would be a rematch of the Australian Open final, won by Djokovic. German Simon Stadler will face Djokovic on Thursday after beating Frenchman Julien Benneteau 7-5, 6-1.