Paris Masters : Roger Federer, Novak Djokovic ease into quarterfinals

• Nishikori to face Federer in the quarterfinals • Dzhumur withdrew from back problem when Djokovic was leading 6-1 2-1 • Russian Karen Kachahanov beat Joshn Isner 6-4 6-7(9) 7-6(8) In his quest...