(Adds quotes) * Top seed races through to quarter-finals * Djokovic plays down shoulder concerns By Pritha Sarkar LONDON, June 30 (Reuters) – If there were fears Novak Djokovic’s double-fisted backhands may malfunction after a heavy fall on his shoulder three days ago, they were allayed on Monday by a show-stopping crosscourt service return on match point. Running to the net to shake hands with his French victim, Djokovic’s celebrations were briefly put on hold as he discovered that his opponent had the temerity to challenge what the top seed thought was the shot of the match. The 6-3 6-4 7-6 (5) victory earned Djokovic his 21st successive grand slam quarter-final date – his sixth at Wimbledon – and a last-eight showdown with Croatia’s Marin Cilic. I had two days off and recovered a little bit,” Djokovic told reporters after registering his 35th consecutive victory against French players.