PTI:Top seed Roger Federer slipped back into play with a confident 7-6 (7-2), 6-4 win over Robby Ginepri to advanced into the third round of the Madrid Masters.
This is his 39th straight victory against an American.
Federer, who has played only one Davis Cup weekend since winning a fourth straight US Open in September, admitted that he had to struggle with early nerves on his way to victory in just under 90 minutes after a first-round bye.
"At the start I didn't feel great. I had to adapt. Thank god I served my way out of trouble," he said after the win on Tuesday. "I'm happy I won, it was not easy. All in all I'm pretty happy with my performance."
The Swiss, winner of six titles this season including three of the four majors, said he was pleased to be defending the Madrid title. Federer had failed to play as a holder this month in Tokyo due to fatigue.
"I missed it two years in a row Coming back and winning last year made me feel good," said Federer. "I took a rest to be 100 percent here. I'm eager to play again."
German Tommy Haas suffered a second-round setback as he tries to maintain eighth place in the race to the season-ending championship next month in Shanghai.
With four spots still on the line, the 11th seed can ill afford the 6-4, 7-5 loss he took against Argentine Juan Monaco.
The German's fate may eventually be decided by his rivals in a race where 14 points separate the eighth through 14th provisional contenders.
Another German Nicolas Kiefer won his first career match in Madrid, reaching the second round 7-5, 6-3 over Federer's Davis Cup teammate Stanislas Wawrinka.
Kiefer, ranked 112 as he makes a comeback from a year of wrist and knee injuries, last played in the Spanish capital in 2005, losing to Karol Beck.
In 2002 at the inaugural edition, he never got out of qualifying rounds. Kiefer has limited exposure in Spain, having played just three previous ATP-level events in the country, two of them in 2001.
Croatian Ivo Karlovic brought mountain-climbing Russian Marat Safin back down to earth as the tallest man in tennis produced a straightforward 6-3, 6-4 first-round rout.
It took just 57 minutes for the Croatian, who won the weekend Stockholm Open, to take victory in the ninth of his last 10 matches after also reaching the Tokyo semis.
Safin, who joined a September Russian expedition for the opening stages of a climb to the sixth-tallest mountain in the world in Tibet, may be pondering his loss of altitude on court.
Huge-hitting Karlovic ended the match with his 17th ace, running his season total to 1,152, well short of the all-time best of 1,477 set by compatriot Goran Ivanisevic in 1996.
The winning effort was enough to demoralise Safin, a former number one now standing 36th after recovering over the past few seasons from the effects of a knee injury.
"I just want to finish this season and start slowly preparing for 2008," said Safin.
The 27-year-old won Madrid in 2004, then backed it up a fortnight later by lifting the Paris Bercy Masters.