Serbia's Novak Djokovic reacts after losing his match against USA's Sam Querrey All-England Lawn Tennis & Croquet Club, Wimbledon, England, July 2, 2016. [Photo/Agencies]

LONDON - Novak Djokovic is fallible after all, as American powerhouse Sam Querrey proved in stunning fashion to stop the Serb's seemingly unstoppable charge towards a calendar year Grand Slam at a rain-hit Wimbledon on Saturday.

The 28th seed boomed down 31 aces and repelled an attempted Djokovic comeback to win a third-round match that began the previous evening 7-6(6) 6-1 3-6 7-6(5).

Top seed and defending champion Djokovic had trailed by two sets overnight after the Court One clash was stopped by rain on Friday but such is the 29-year-old's aura that most expected him to turn it around, just as he did when faced with a similar predicament against Kevin Anderson last year.

On the resumption, the Serb won the opening four games before another rain delay, but wobbled slightly before securing the third set to halve the deficit.

Djokovic appeared distracted at times, looking up to Boris Becker in his coaching box, but was primed to level the match when he served at 5-4 in the fourth, only for Querrey to break.

When yet another rain delay sent the players off court for an hour with Djokovic serving at 5-6, he returned to take it into a tiebreak.

Querrey went 6-4 ahead and though Djokovic saved one match point with an ace, he shanked a forehand into the tramlines to end his 30-match winning streak in Grand Slam play - a run that meant he arrived at Wimbledon holding all four major titles.

Defeat scuppered his hopes of becoming the first man to win all four majors in a year since Rod Laver in 1969 and was his first loss before the quarterfinal of a major since the 2009 French Open when he also bowed out in the third round.