Del Potro reached the final at Indian Wells last week, but was unable to see off 89th ranked Kamke.

CNN: Injury heartache for Williams at Miami Masters

Defending SAP Open champion Milos Raonic beat his predecessor as ATP Newcomer of the Year, Tobias Kamke of Germany, to reach the quarterfinals.

CNN: Monfils pulls out as Roddick battles through in San Jose

Federer will play home favorite Julien Benneteau in the next round after the Frenchman prevailed 7-6 7-5 5-7 0-6 6-4 against Germany's Tobias Kamke.

CNN: Cash: Only injury can deny Nadal in Paris

But one man who won't be on court is fifth seed Juan Martin del Potro after he was sent crashing out in the second round by Tobias Kamke.

CNN: Injury heartache for Williams at Miami Masters

"Maybe I did, but I don't remember, " said the Swede, who will play Albert Montanes in round three after the 29th seed waltzed past Tobias Kamke 6-3 6-2 6-1.

BBC: Roger Federer overcomes Alejandro Falla at French Open

The French, whose last Davis Cup triumph was in 2001 will now play Argentina after they whitewashed Germany in Buenos Aires -- David Nalbandian and Horacio Zeballos winning their doubles match against Christopher Kas and Tobias Kamke 6-1 6-4 5-7 6-2.

CNN: Czech Republic win 7-hour Davis Cup doubles marathon