Clive Brunskill/Getty Images

Gilles Muller shocked the tennis world by beating an in-form Rafael Nadal in the round of 16 at the 2017 Wimbledon Championships on Monday, defeating the two-time champion 6-3, 6-4, 3-6, 4-6, 15-13 to reach the quarter-finals.

Nadal's enthralling run of form in 2017 came to a screeching halt due to a ferocious performance from his Luxembourger foe, who survived a tug-of-war that lasted four hours and 50 minutes to clinch just his second major quarter-final.

Marin Cilic awaits Muller in the next round after he trounced Nadal's Spanish compatriot Roberto Bautista Agut, 6-2, 6-2, 6-2, on Manic Monday.

Nadal maintained his composure even after such an agonising defeat:

Two left-handed contenders of this calibre were always going to make for an intriguing bout, and the pair lived up to expectations with a roller-coaster duel on Court No. 1.

Nadal could have been forgiven for being caught somewhat off guard in the first set, where Muller's aggression from the serve and follow-up play kept things tight as the latter carved out an early a 3-2 advantage.

That approach helped Muller notch the first (and only) break of the first set to lead 4-2 thanks to Nadal hitting the net on a stern return. Both players served out the remainder of their points to mark a surprisingly clean set for Muller, who ended a substantial Nadal streak, per tennis writer Jose Morgado:

Video Play Button Videos you might like

The ensuing second set was over in a flash, as during the opening seven games, the loser managed to get more than one point on the board only twice, a sign of how vital the service battle had become.

Nadal avoided any unforced errors in the first set but changed for the worse in the second, as he surrendered four, per the IBM Slamtracker.

One of those again happened to come at a potentially decisive moment, when his sliced return skidded into the net to seal another break in Muller's favour to lead 5-4, although tennis reporter David Law wasn't all surprised:

The Nadal that returned to play in the third set was different than the one witnessed up to that point in the match—or at the very least, Muller's defiance had considerably lessened during the interval.

Nadal's trusty left hand helped him win to love in the opener and defend his own serve with relative ease while breaking Muller to lead 3-1 and then 4-1, although Stuart Fraser of The Times indicated the odds were still against him:

That three-game streak ignited a fire in Nadal that burned until the end of the third set, and it was the Spaniard who this time came away with the smash-and-grab, albeit not before Muller fended off two set points.

One came under the impression Nadal was far more likely to snatch the win the longer their clash raged on, and again he picked his moments wisely in the fourth, breaking Muller in near-identical fashion to the previous set.

While Nadal failed to concede more than one point in any of his five services games during the set, a double-fault from Muller in the fifth gave Nadal the opening he needed to put together a three-game spree once again.

The 31-year-old drew level at two sets each after seemingly draining Muller of all fortitude on his return, but a steelier response emerged from Luxembourg's finest in the decider as Match of the Day's Gary Lineker hailed the favourite's revival:

Despite shifting the momentum in his favour, Nadal continued to see resistance from a relentless Muller, whose serve gave him a major advantage in the short rallies, while his foe excelled in longer exchanges.

Nadal's return handed Muller some trouble, and although the same couldn't always be said vice versa, the underdog nevertheless kept things level at 4-4 without having to face deuce in the fifth set until that point.

The 6'4" dark horse forced two match points out of his foe in the 10th game before Nadal responded with resolve to tie matters up at five games apiece. But it wasn't long before Muller was back on the baseline, and sure enough, he served to love for the second game in succession.

The balance of the points meant the Spaniard would be under the screw for the remainder of their clash, per Ben Rothenberg of the New York Times:

Muller continued to stand the test of an enemy who would overwhelm others but struggled to keep up with his serve. The dark horse clinched advantage before taking the game to lead, with aces still playing a factor in his rise, as tennis writer Christopher Clarey noted:

But Nadal was even keeping up in that regard and boasted 20 aces to his opponent's 24 as they raged into the 14th game of their meeting—not to mention the second hour of their fifth set—before Muller gleaned the slightest of cushions at 8-7.

The tug of war broke the four-hour mark as the pair dragged each other into a 20th game with Muller holding a 10-9 lead. At that point, Nadal had missed four break-point opportunities:

The Wimbledon crowd rallied around Nadal with every point he claimed, capitalising on any Muller error to eventually draw 13-13. Muller had found at least some answer to Nadal's serve, and to an extent, vice versa.

Muller showed great calm with a backhand to again go ahead at 14-13, but his critical piece of composure came a game later, when he opened up two match points and watched Nadal's forehand sail long to settle the match.

The left-handed Muller handed Nadal a tough draw in the fourth round, although Cilic will be a difficult foe to down in his own respect, particularly with Muller fresh off a match that lasted close to five hours.

Nadal has not advanced past the round of 16 at Wimbledon since 2011, when he lost in the finals to Novak Djokovic.