By Clare Lovell
LONDON (Reuters) - Top seed Novak Djokovic suffered some jittery moments under the big-serving onslaught of Marin Cilic on Wednesday before changing his shoes and pulling his game together to win 6-1 3-6 6-7(4) 6-2 6-2 for a place in the Wimbledon semi-finals.
The Serbian former champion began efficiently, rattling through the first set in 27 minutes on a sunny but subdued Court One.
The crowd had half an ear on Henman Hill, where big-screen spectators whooped and groaned through champion Andy Murray's defeat by 11th seed Grigor Dimitrov.
Djokovic's intensity dropped in the second set. The world No.2 slipped and slid in the baseline dust and his towering Croatian opponent grabbed a break of serve using his big forehand to pummel the six-times grand slam champion.
"We could hear the crowd during the match and it was a bit distracting; but no excuses, we had to concentrate," Djokovic said.
"It was a tough five-setter. Coming in I knew Marin would play aggressively.
"He raised his game but I allowed him to come back into it. I was too passive on my strokes and he used his opportunities, but I managed to find the right pace when I needed it."
The pair fought a tight third set, watched by their celebrity coaches Boris Becker and Goran Ivanisevic, before normal service was resumed.
Djokovic donned a new pair of shoes, upped the pace and raced into his 23rd semi-final, where he will meet 23-year-old Bulgarian Dimitrov.
"After I changed my shoes in the fourth set I played well - I will keep them to play Grigor Dimitrov," a smiling Djokovic said.
"It was a big win for Grigor. He's on fire this last six months ... he's not lost a match on grass this year. He's the man to beat."
(Editing by David Goodman)