LONDON –  Novak Djokovic won the second set 6-4 to level his Wimbledon final Sunday with seven-time champion Roger Federer at one set each.

Federer won the first set 7-6 (7).

Djokovic fell awkwardly in the first game of the second set and called for a trainer immediately after he broke Federer’s serve to take a 2-1 lead. The trainer worked on Djokovic’s left ankle.

It was only the second time this tournament that Federer had his serve broken — the other came in Federer’s quarterfinal win over fellow Swiss Stan Wawrinka, when he dropped his only set of the tournament before the final.

Watching the final from the Royal Box were Prince William and his wife, Kate, David Beckham and actors Bradley Cooper, Samuel L. Jackson and Chris Hemsworth.