LONDON (AFP) - Novak Djokovic praised Nemanja Vidic after the Manchester United football captain gave up his Centre Court royal box seat to help roar the world No.1 tennis player into the Wimbledon semi-finals on Wednesday.

Djokovic reached his 13th consecutive Grand Slam semi-final with a 7-6 (7-5), 6-4, 6-3 win over Czech seventh seed Tomas Berdych in a match played on Court One.

Vidic, a Serb compatriot of the 2011 champion, opted for the second show court to sit with his wife Ana in the Djokovic box, while his former Manchester United manager Alex Ferguson stayed on Centre Court.

"He came to see me play. I was very much delighted to see him in our box today and watching the match and supporting me," said Djokovic.

"It's the first time he actually came to watch me. I've watched him before in the national team a few times. We met briefly. He's a big star in our country."