Novak Djokovic
Djokovic prevailed in one of the great grand slam semi-finals.

Novak Djokovic provided another example of his superhuman tendencies to reach his second Wimbledon final after defeating Juan Martin del Potro in a match for the ages at the All-England Club.

Djokovic defeated Del Potro 7-5 4-6 7-6 6-7 6-3 to reach the final where he will face either Andy Murray or Jerzy Janowicz after the longest semi-final in Wimbledon history and one that will go down as the greatest in the grand slam era.

The world No.1 had saved two match points in the fourth set tie-break, but won four successive points to take the match to a deciding fifth set.

But Djokovic held his nerve after breaking a tireing Del Potro, who was making his semi-final debut at SW19, to serve out the match as he goes in pursuit of his ninth major crown.

Neither Djokovic nor Del Potro had dropped a set going into a repeat of the bronze medal match at the Olympic Games last summer, but something had to give in the opening exchanges.

While Del Potro's power game, which had seen him blow away David Ferrer in the quarter final, was absent in the early stages, Djokovic was unable to generate timing on his formidable backhand in a tense, if not scrappy opening.

It was the Serbian however who took the early advantage, breaking Del Potro in the 12th game to take the opening set 7-5.

The former US Open champion was unperturbed despite the much fancied Djokovic hitting the front as he reeled off 10 successive points in the midst of the second set to lay the platform to square the match.

No quarter was given in the third set, which saw Djokovic spurned three break points, but the six-time grand slam champion prevailed in the tie-break putting him on course for a second final at the All-England Club.

And the No.1 seed appeared on the brink of the final after an exhilarating fourth set when he broke for a 4-3 lead, only for Del Potro, who came into the contest with question marks over his suspect knee injury, to break back immediately. Despite missing a chance to serve for the fourth set, the South American fought through for a second tie-break.

Djokovic forged two match points after leading 6-4, but following a memorable rally between the pair and stunning back-hand return from Del Potro, the Argentine crowned the finest of all comebacks by winning the tie-break and forcing a deciding set.

The pair both had chances early in the second set to break, Djokovic producing a backhand when required before the 2011 Wimbledon champion was error stewn in his approach as the eighth seed began to show the afteraffects of his injury past as the match ticked over into the longest of his grand slam career.

Like a ruthless champion Djokovic made no mistake is exposing his opponent's weakness, as Del Potro went long with a forehand in the eighth game to to create the break and allow Djokovic to serve for a place in the final.

Saving a break-point of his own along the way, Djokovic made no mistake on his third match point with a brilliant backhand down the line - a crescendo on the longest Wimbledon semi-final in history of four hours and 43 minutes and truly the greatest.