This much is certain about Nick Kyrgios' upset of top-seeded Novak Djokovic in the quarterfinals of the Acapulco ATP 500 tournament Friday morning: You could see this one coming.

What is less certain is how the result will impact either player as the two big Masters 1000 events loom in the coming weeks.

Kyrgios relied on a savage combination of consistency and raw power to craft his 7-6 (9), 7-5 upset of Djokovic, raining down 25 aces and numerous service winners. Kyrgios can topple any icon when he does that, as Roger Federer and Rafael Nadal can attest from personal experience.

Djokovic picked a bad time to play his first match against the Aussie hellion. The deposed No. 1 has brought the art of being squared away and fully prepared to the level of art. Yet Djokovic abandoned his trusted -- and remarkably productive -- routine to take a last-minute wild card into the Acapulco event. The Monte Carlo resident arrived in steamy, hot Acapulco just 48 hours before he was scheduled to play his first match.

Hard to believe, but Novak Djokovic has won only a single title since last July. REUTERS/Henry Romero

We don't really know why Djokovic broke with tradition and chose to enter Acapulco. That second-round loss to Denis Istomin at the Australian Open certainly left him short of matches this year as well as eager to wipe the slate clean. Perhaps more importantly, Djokovic is well aware of the great inroads his rivals have made since Andy Murray yanked Djokovic's hands off the throat of the game last fall.

Nadal, now ranked No. 6 but surging out of his slump and coming off an Australian Open final, was the top name entered in Acapulco. Djokovic may have sensed an opportunity to tinker inside Rafa's head a bit before the "King of Clay" gets his feet firmly planted on solid ground again. The thought of a fully confident Nadal steamrolling into Roland Garros, where Djokovic won last year, can't be a pleasant one for the defending champ.

Djokovic played two solid matches in Mexico. But he ran out of steam against rising star Kyrgios. After the Aussie won the first-set tiebreaker, Djokovic managed to hold serve until 5-6 in the second set, whereupon he made three ghastly unforced errors to give Kyrgios a match point. Bang! Kyrgios won it with a forehand winner.

"It's a big win," Kyrgios told the press afterward. "I was a little bit nervous because I'm sure the crowd was rooting for Novak. He's one of the greatest players of all time, but I'm playing with confidence. My serve is the best part of my game, and I had one of my best serving matches tonight."

Djokovic will be able to tell himself that Kyrgios just got hot. Everyone knows that the 21-year-old mercurial Aussie can do that. But the loss also calls into question Djokovic's decision to take the wild card. Maybe the Serb who utterly dominated tennis until midsummer last year needs to do some deep thinking about his situation, including, his coaching situation. Boris Becker shepherded Djokovic through his recent years of domination, but Djokovic let him walk at the end of last year.

Djokovic prides himself on keeping his cool, on taking things in stride. When stunned reporters asked Djokovic what he "takes" from his loss to Istomin in Australia, he cavalierly replied, "I take my bags and I go home. Lessons are always learned every single day, not just when you lose."

It never helps to panic, but you also have to wonder: At what point does playing it cool become a form of denial?

Djokovic put up a nice vengeance win against Murray in Dubai to start his year. Did Djokovic then take too much for granted and take his foot off the gas? He lost in Australia and now Acapulco. The last tournament he won before Dubai was the Canada Masters 1000, way back in July.

No matter how impressive a player's skills and style are, they are not the source of an aura of invincibility. Federer can tell you that. That precious aura comes from one thing only: a player's record. Right now, Djokovic is very busy becoming a player whom other players believe can be beaten. And right now, Kyrgios, Nadal and Murray are taking steps toward seeming invincible.

That's how it works in tennis, and it is bound the make the coming weeks interesting and stressful, even for a man as philosophical and chill as Novak Djokovic.