LONDON, July 5 (Reuters) - Novak Djokovic withstood a ferocious onslaught from Juan Martin Del Potro to subdue the Argentine 7-5 4-6 7-6(2) 6-7(6) 6-3 in a titanic Wimbledon semi-final on Friday.
The top seed needed all his skill and fighting spirit to tame the eighth-seeded Del Potro who made light of his knee injury to keep the world number one on court for four hours 43 minutes, the longest semi-final ever seen at Wimbledon.
"It was one of the best matches I've been a part of, one of the most exciting. It was so close," said a hugely relieved Djokovic.
"I could not separate us, apart from when I was 2-1 up and a break up, and I dropped serve. That's why he's a grand slam champion. He came up with some top shots...credit to him."
Djokovic broke in the 12th game of the first set to win it 7-5 but former U.S. Open winner Del Potro took the Serbian's serve midway through the second set and levelled the match on a baking Centre Court.
Del Potro saved three set points at 5-6 in the third but Djokovic stepped up his level to romp through the tiebreak 7-2.
The top seed struck again with a break in the seventh game of the fourth set but Del Potro broke straight back and saved two match points in an incredible tiebreak before taking it 8-6.
Djokovic broke again to lead 5-3 in the deciding set and he recovered from 0-30 down to seal victory with a searing backhand down the line.
Djokovic will play second seed Andy Murray or Jerzy Janowicz, seeded 24th, in the final on Sunday when he will bid for his second Wimbledon title and seventh grand slam crown. (Reporting by Ed Osmond, editing by Martyn Herman)