Djokovic digs deep to repel Raonic onslaught

By Martyn Herman LONDON (Reuters) - It has been missing for a while but Novak Djokovic rediscovered his warrior spirit to tame Canada's Milos Raonic 7-6(6) 7-6(5) in a rivetting duel and guarantee progress from his group at the ATP World Tour Finals on Tuesday. The 29-year-old Serb's recent malaise has cost him the world number one ranking he held for 122 weeks but when backed into a corner by an inspired Raonic, he responded in the belligerent manner that has earned him 12 grand slam titles. Wo