Wimbledon, England (CNN)The upset bug has struck Rafael Nadal -- again -- at Wimbledon.
When the two-time champion lost to Dustin Brown 7-5 3-6 6-4 6-4 in the second round on Center Court Wednesday, it marked the fourth time in a row he had fallen to a player ranked 100th or lower at the All England Club.
In this case, Brown -- a dreadlocked German with Jamaican ancestry who once traveled around Europe in a camper van to keep his career going -- was a 102nd-ranked qualifier. But he did have history of beating Nadal, last year at a Wimbledon warmup event in Halle.
Brown, 6-foot-5, is far from orthodox. He serves and volleys relentlessly, slaps forehands and attempts more than a few drop shots.
It mostly all worked, to Nadal's dismay.
"If I would stay back and rally with him left, right, that would not be a very good match for me," Brown, who sports a tattoo of his dad on his left side, told reporters. "Obviously I try to play my game."
Nadal said he entered Wimbledon in a positive frame of mind, or at least better than what he had felt for much of this season, even after he lost in the quarterfinals at the French Open -- a tournament he has won a record nine times -- and dropped in the rankings.
He triumphed at an event in Germany to begin his grass-court campaign, but was seeded a lowly 10th in southwest London.
Once he relinquished a break advantage in the first set against Brown, the doubts he experienced earlier in 2015 appeared to resurface and parts of his game crumbled.
Looking unsure of himself, his serve all but vanished and his once feared forehand went astray. His statistics of 42 winners and 15 unforced errors hardly seemed appropriate.
"It's not the end," vowed Nadal, the 14-time grand slam winner. "It's a sad moment for me ... but life continues. My career, too.
"I have to keep going and working more than ever to try to change that dynamic."
Lukas Rosol, then the world No. 100, eliminated Nadal in the second round in 2012; Steve Darcis, then ranked 135th, sent the Spaniard packing in the first round in 2013; and Nick Kyrgios, at the time the world No. 144, knocked him out in the fourth round last year.
This season it was Brown's turn.
"All the kids that play tennis dream about being able to play on that Center Court," said Brown. "Playing against him there is special.
"Also, being able to put that performance together, it was definitely very difficult and I'm very happy that I held it together for the whole match."
Brown -- a grass-court specialist if ever there was one -- knocked off his second Wimbledon champion in London.
After the 30-year-old produced an angled ace on his third match point, he emulated his feat of 2013 when he downed Lleyton Hewitt -- like Nadal a former world No. 1, too. Brown hit 13 aces altogether Thursday and won nearly 80% of his first-serve points.
Nadal's loss came as the likes of Roger Federer, Andy Murray and defending women's champion Petra Kvitova all cruised into the third round on a hot but manageable day at SW19. Wimbledon had record temperatures of about 36 degrees Celsius (97 Fahrenheit) on Wednesday.
Brown's reward is a third-round meeting with Serbian Viktor Troicki, whom Nadal defeated in the Stuttgart final last month.
Things didn't start well for Brown, though. He trailed by an early break.
Reversing the deficit made for an obvious turning point in the first set.
"After losing the first set, you are under pressure the rest of the match," said Nadal.
A more subtle shift allowed Brown to recover in the third and ultimately take control.
With Nadal holding the momentum, the Mallorcan failed to take advantage of a creaking Brown in the latter's opening service game. He paid the price in the fifth game, broken a point after hitting two double faults in a row.
Now facing an uphill battle -- and no longer the player who rallied to win two five-setters en route to the crown in 2010 -- Nadal fell behind 3-1 in the fourth.
He was given a lifeline when saving two match points at 3-5, but after Brown donated a double fault to begin the ensuing game, Nadal didn't capture another point.
Federer, meanwhile, wasn't really tested against Sam Querrey and not many would have forecast a tight contest to begin with. Federer had only lost prior to the third round at a major once since the middle of 2003 and his 36th-ranked American opponent held a 0-8 record versus top-10 opposition at the grand slams.
But if the 6-4 6-2 6-2 result was fairly predictable, Federer's artistry on one particular stroke Thursday was far from routine -- even for him.
The Swiss struck what had to be the shot of the tournament with his 'tweener -- or shot between the legs -- at 4-2 in the second set. Facing the net, it turned out to be a perfect lob that drew an error.
Twitter went into overdrive and Querrey, a laid back Californian, joined in on the praise.
"He's got that aura around him," Querrey said of the record 17-time men's grand slam champion. "He hit that shot between his legs. He hit some amazing passing shots, hit some half volleys.
"He hits shots that other guys don't hit. You want to go over and give him a high five sometimes, but you can't do that."
The ever chilled Federer, who next plays big-serving Aussie Sam Groth, wouldn't have minded.
Murray, who could have encountered Nadal in the quarterfinals, didn't linger against Dutchman Robin Haase, one of those players Nadal defeated in five sets at Wimbledon in 2010. The 2013 champion cruised 6-1 6-1 6-4. Trying to stop the in-form Scot in the third round is Andreas Seppi.
For so long the lone British man who makes the third or even second round at a grand slam, Murray has company this year after wildcard James Ward beat Jiri Vesely.
The last time two British men featured in the third round at Wimbledon was in 2002, when, in no surprise, Tim Henman and Greg Rusedski were the duo.
Kvitova needed just 35 minutes to overcome Kiki Bertens in the first round. It was 58 minutes against Kurumi Nara -- 6-2 6-0 -- on Thursday.
As for Nadal, despite his loss, he didn't lose his sense of humor.
When asked if he would stay in his premises near the venue and remain in London for a few more days, he quipped: "I don't have more work in London, so ... if you want to use the house, it's going to be free tomorrow."