Former world No. 3 David Nalbandian made an impressive ATP return Monday after being out since April with a left hamstring injury, beating Rajeev Ram 6-4, 6-0 at the Washington Classic. The 2002 Wimbledon runner-up had not played a tour event since losing on clay at the Monte Carlo quarterfinals, but won twice without dropping a set to lead Argentina past Russia last month in a Davis Cup quarterfinal tie. Another veteran hard-hit by injury, US wild card James Blake, was ousted by US qualifier Ryan Sweeting 3-6, 6-3, 6-4. Blake, now 10-12 this year, missed two months with a right knee injury. Czech top seed Tomas Berdych, playing his first tournament since losing to Nadal in the Wimbledon final, was among 16 players who had first-round byes. Slovenian qualifier Grega Zemlja avenged a first-round loss at this year's Australian Open by ousting Germany's Benjamin Becker 6-2, 6-3. He faces US second seed Andy Roddick on Tuesday. Germany's Michael Berrer beat Slovakian Karol Beck 6-3, 6-4 to reach a second-round match Tuesday against Spanish third seed Fernando Verdasco. “Since Davis Cup, I'm feeling a little better,” Nalbandian said. “I feel great. I need to play more matches. I feel fit. Results are going to come.” Nalbandian underwent right hip surgery in May of last year and missed nine months, then suffered a torn right leg abductor muscle in his comeback event last February in Argentina before suffering his latest setback. “Doctors told me it's good,” Nalbandian said. The 28-year-old South American wild card entrant advanced to a second-round match against Swiss seventh seed Stanislas Wawrinka at the 1.4 million-dollar hardcourt event, a tuneup for the US Open which begins in four weeks. “I haven't played a lot of matches. That's not good,” Nalbandian said. “It's tough when you are out of the tournaments for a long time. It's not easy to get here and be competitive. You have to pay attention to every little thing.” Nalbandian, a career-high third in the world in 2006 who has slid to 117th in the rankings, improved to 12-3 in ATP matches this year, two of his losses coming to world number one Rafael Nadal and second-ranked Novak Djokovic. When he will reach peak form remains uncertain but form and confidence are growing with every match. “It's tough to say,” Nalbandian said. “Every time I go on the court I feel a little better. But it seems like it's never enough. I'm still working on it.” Sweeting, who next faces Frenchman Michael Llorda, called it “my best win for sure”, adding, “I just tried to keep the ball away from his forehand as much as possible.”