American Michael Russell pulled off the first upset of the 2011 Los Angeles ATP tournament, rallying to topple sixth-seeded Russian Dmitry Tursunov 6-7 (5/7), 6-0, 6-2. Tursunov, ranked 46th in the world and a title winner already this year at Rosmalen, saved two set points against his serve in the 12th game of the opening set, holding to force the tiebreaker. After eking out the victory in the first set, however, Tursunov went flat and the 110th-ranked Russell went on to triumph in 1hr 52min. Tursunov was the only seeded player in action Monday. Taiwan\'s Lu Yen-Hsun emerged victorious from a potentially tricky first-round match, downing American wild card Robby Ginepri 6-4, 7-5. Lu needed little more than an hour and a half to defeat Ginepri, who is coming off a serious elbow injury and playing only his second ATP tournament of the year. But Lu said he knew Ginepri, owner of three career titles, would be a difficult test, even if his injury layoff has seen his ranking plummet to 370th in the world. \"He just got back, but everyone knows he\'s a fighter,\" Lu said. \"I expected a lot of deuces. I just told myself to be strong, to keep up with him and try to win.\" Lu admitted he found it a bit difficult to adjust to the conditions in Los Angeles after the sticky humidity last week in Atlanta, where he reached the quarter-finals But he was pleased to get through to a second-round clash with third-seeded Cypriot Marcos Baghdatis. Juan Martin del Potro is also looking ahead -- in particular to the US Open, scene of his breakthrough Grand Slam triumph in 2009. \"I am very excited to come back to New York,\" said del Potro, who didn\'t get a chance to defend his title at Flushing Meadows in 2010 after a wrist injury cut short his season. \"If I could start to play tomorrow I would. First I have very important tournaments before. \"This tournament it\'s important for me -- it will be my first tournament after clay and grass season.\" The Argentinian is the second seed behind American Mardy Fish in the $619,500 tournament, with Baghdatis and Brazil\'s Thomaz Bellucci rounding out the top four, who all have first-round byes. Del Potro, who has painstakingly climbed from 484th in the world rankings to 19th, said he was ready to put the wrist injury behind him and just focus on his game. \"It has been a very long while since my wrist injury. Now I\'m OK and getting better with my tennis, with my mind, and all my problems are in the past,\" said del Potro, who joked that he had answered so many questions about the injury that he now just pushes \"play\" and starts talking when asked about it. He\'s less concerned with the past than with the future and his goal of returning to the top 10. \"I still believe in my game,\" said Del Potro. \"I\'m very confident with my level at this moment.\" American Ryan Sweeting, who captured his first career title at Houston in April, turned the tables on Somdev Devvarman, notching a straight-set victory over the Indian who had beaten him in the first round at Atlanta last week. Sweeting triumphed 6-4, 7-6 (8/6), but Devvarman turned it into a dogfight at the end as he recovered an early second-set break then broke Sweeting in the sixth game to take a 4-2 lead. Neither player could hold serve for the next three games -- until Sweeting held to knot the score at 5-5. Sweeting needed three match points to put away the tiebreaker and said he was happy to avenge his Atlanta defeat. \"Any time you play Somdev you know it\'s going to be a battle,\" he said. \"It\'s never easy.\"