Top-ranked defending champion Novak Djokovic withstood back spasms throughout the second set to defeat Tomas Berdych 6-3, 6-3 and reach the ATP and WTA Miami Open semi-finals. Djokovic, trying to match Andre Agassi’s record of six Miami titles with his third in a row, will play Belgian 15th seed David Goffin on Friday for a berth in Sunday’s final. “Due to windy conditions on the court, it was hard to find a good rhythm to serve,” Djokovic said.