Rafael Nadal extended his reign at the top of the Emirates ATP World Rankings after capturing his third US Open title and 16th Grand Slam overall in Flushing Meadows over the weekend. Nadal, 31, has now accumulated 9,645 ranking points, giving him some significant breathing room over Roger Federer (7,505) in the race for season-ender world’s no.1 ranking.

Battle for ranking points

But the battle is far from over. More ranking points are still up for grabs over the coming weeks with the Shanghai Masters, Paris Masters and London still left on the ATP Tour schedule.

Federer, who captured two of the four available Grand Slam titles this year, has already expressed his desire to retake the top ranking. He’s already committed to play in at least five tourneys over the course of two months, two of which are ATP 1000 Masters events and the other is points-rich ATP Tour Finals in London.

“Now I have Laver Cup, Shanghai, Basel, Paris, and London,” Federer said after his quarterfinal loss to Juan Martin Del Potro at the US Open. “That's my schedule, and it won't change. I hope I'm fully recovered and 100 percent fit when Laver Cup comes around. When that's over, I hope I'm going to arrive really early in Shanghai to really get ready and make it a priority for me to win that tournament.”

The last time Federer held the top spot in the world rankings was in 2012, the year he captured his seventh Wimbledon Championships and a silver medal in the London Olympics.

After that, Federer waited five long years until he tasted Grand Slam success again.

His surprising Australian Open title run opened the gates for the Swiss to achieve greater feats this year, as he followed it up with back-to-back wins at Indian Wells and Miami and nabbed his 19th Grand Slam title in his marquee event at All-England club.

Showdown beckons for Federer, Nadal

A US Open semifinals clash with Nadal would have given Federer the opportunity to take the no.1 spot. However, Del Potro’s stunning quarterfinal upset victory not only prevented the Swiss from his 20th Grand Slam crown but delayed his march to the top of the rankings.

Yet, Federer is the only player in the top-10 that has a real shot at toppling Nadal.

The Spaniard would have easily secured the no.1 ranking all the way to November because he has zero ranking points to defend, thanks to his decision to end his 2016 campaign early.

Unfortunately, he’s not the only player who benefits from an early layoff last year. Federer also pulled out from the tour as early as September because of knee and back problems. Like Nadal, the Swiss has zero points to defend and can amass more ranking points this coming fall.

The unique situation sets up an interesting tug-of-war between Nadal and Federer in the succeeding weeks. In fact, there’s a strong chance a Nadal-Federer showdown for the no.1 ranking could take place in multiple sites such as Basel, Paris and the season-ending ATP World Tour Finals in November.