Florian Mayer\'s singles victory over Igor Andreev clinched a first-round win for defending champion Germany at the World Team Cup tennis event Monday. Meyer\'s 6-2, 7-6 (9-7) decision over Andreev gave the Germans an insurmountable 2-0 advantage against Russia in the tie, garnering Germany a 1-0 record in the round-robin tourney\'s Blue Group. Germany completed the triumph when the doubles team of Mayer and Christopher Kas bested Russia\'s Igor Kunitsyn and Dimitry Tursunov 6-4, 3-6, 10-8. The Czech Republic also took a point Monday, beating Japan 2-1 in the Red Group with the help of a doubles victory by Radek Stepanek and Frantisek Cermak, who dispatched the Japanese tandem of Tatsuma Ito and Go Soeda 6-2, 7-6 (7-4). Serbia, meanwhile, went to 1-0 in the Blue Group by besting Croatia 2-1 thanks to Janko Tipsarevic\'s 6-0, 6-0 rout of Lovro Zovko. Argentina, which defeated the United States Sunday, finished off the victory with a 7-6 (7-2), 6-4 doubles win Monday.