- Andy Roddick crashes out of the first round of the ATP 500 event in Memphis
- Roddick won his 30th and last Tour title at the same event last year
- 2011 runner-up Milos Raonic advances after a win over Sergiy Stakhovsky
- The Canadian is the only man to have won two Tour tournaments in 2012
At last year's Regions Morgan Keegan Championships, former world No. 1 Andy Roddick defeated rookie Milos Raonic in the final to claim his 30th ATP Tour title.
But the 2003 U.S. Open winner's form has declined over the last 12 months, his latest defeat coming on Wednesday when he was beaten 7-6 (10-8) 7-5 by Belgium's Xavier Malisse in the first round of the Memphis event.
Four-time grand slam finalist Roddick has struggled for fitness in 2012. The 29-year-old sprained his ankle in San Jose last week having already been forced to pull out of last month's Australian Open at the second-round stage with a hamstring injury.
But despite his recent injury troubles, the current world No. 27 refused to feel sorry for himself after his first career loss to Malisse -- who will play Germany's Benjamin Becker in the second round.
"I hit the ball okay, I just didn't hit it well when I had to," Roddick, who last year finished outside of the top 10 for the first time in 10 years, told the ATP World Tour's official website.
"I had nine, ten years of a pretty clean bill of health overall. I think for me to feel too sorry for myself now, it probably wouldn't be okay.
"I know Mardy (Fish), for instance, had wrist surgeries in the middle of his career, 22, 23-years-old, so I didn't have that. It's the first time I'm really dealing with anything significant."
While Roddick is on the decline, 21-year-old Canadian Raonic is the rising star of men's tennis.
Fresh from defending his SAP Open title in San Jose last week, the fourth seed recorded a 6-2 7-6 (7-3) victory over Latvia's Ernests Gulbis.
But Raonic, the only man to have won two Tour titles in 2012, said he was disappointed with aspects of his performance after setting up a clash with the Ukraine's Sergiy Stakhovsky.
"The match was good," said the world No. 35. "I felt like I did the things I needed to. I don't feel I played my best, but as the match progressed I got better and better, and really everything just went my way.
"I played the big points well and built from there. I'm happy to be able to get through and have another chance to play better tomorrow."
Czech No. 3 seed Radek Stepanek ended a four-match losing streak with a 6-3 6-2 win over American qualifier Bobby Reynolds.
Another home-crowd favorite awaits Stepanek in the second round, after Ryan Sweeting got the better of compatriot and former world No. 4 James Blake.
Uzbekistan's Denis Istomin, who lost to Raonic in the San Jose final, was beaten by Austrian Jurgen Melzer, while seventh seed Kevin Anderson defeated American Robby Ginepri.