Wimbledon may have built its reputation on being an uniquely grasscourt Grand Slam tournament but defending champion Novak Djokovic is happy to play it under a roof, with the lights burning bright. Top seed and world number one Djokovic gave the Centre Court roof the thumbs up on Wednesday after beating America’s Ryan Harrison 6-4, 6-4, 6-4 to reach the third round. With the roof closed after three hours of rain had brought a halt to action on the outside courts, Djokovic was delighted to get a second chance to play the late night entertainer. “It’s hard to prepare for that because you play an indoor match on the Centre Court maybe once every couple of years. 2010 was my only match under the roof aside from tonight’s match,” said Djokovic. “It is quite different. I think the lights were really good. The attendance was fantastic. The crowd enjoyed it. It was a spectacular match from a player’s point of view. “Sometimes it’s good for a change to be under the roof. It makes it more interesting as well I think, if you go to the late hours.” Djokovic’s match with Harrison ended shortly before 10pm (2100GMT) and he goes on to tackle either Czech veteran Radek Stepanek or Germany’s Benjamin Becker for a place in the last 16.