By Shrivathsa Sridhar LONDON (Reuters) -Top seed Jannik Sinner struggled with an elbow problem and was given an almighty scare before advancing to the quarter-finals of Wimbledon after a cruel twist of fate for his 19th-seeded opponent Grigor Dimitrov who retired injured while two sets up.

The 38-year-old overcame a first-set loss to take a 6-7, 6-2, 7-5, 6-4 victory over Italian Flavio Cobolli to advance to the semifinals for the 14th time at the All England Lawn Tennis & Croquet Club. Djokovic has now reached the final four at Wimbledon more than any other men's tennis player, surpassing Roger Federer on Wednesday.