ROME: Roger Federer picked his shots carefully to get by towering Ivo Karlovic 7-6 (7-4), 6-3 and reach the quarterfinals of the Rome Masters. Federer will next face Radek Stepanek, who defeated Peruvian qualifier Luis Horna 6-4, 1-6, 6-3. Also advancing was Australian Open champion Novak Djokovic, who survived a mid-match scare from Igor Andreev before eliminating the Russian 6-3, 3-6, 6-3. Two Americans also made the last eight for the first time in six years. Sixth-seeded Andy Roddick beat rising local favorite Simone Bolelli of Italy 7-6 (5), 6-3 and No. 8 James Blake rallied past Fernando Verdasco of Spain 5-7, 7-5, 6-2. The third-ranked Djokovic will now play Spanish clay-court specialist Nicolas Almagro, who advanced with a walkover when No. 12 Fernando Gonzalez pulled out with a right leg injury.