The stroke that turned Federer's fortunes against Nadal around

The final point of the match lasted just a fraction of a second but summed up months of hard work. Down 5-3 in the second set and serving at 15-40, Rafael Nadal kicked a second serve down the middle of the deuce court, only to see Roger Federer unleash a clean backhand winner down the line.

That fleeting moment left Rafa looking stunned, as he had all match. All he could do was shake his head as he trotted to the net.

It was over in 68 minutes, and frankly, this one took your breath away -- but not in the way we might have expected. Federer won 6-2, 6-3 with a lights-out performance Wednesday to reach the Indian Wells quarterfinals.

Federer's dominance was, to be honest, beyond astonishing, and he can thank his backhand for the supreme effort.

For years, Nadal has exploited that wing -- consistently hitting his high-hopping, lefty forehand to Federer's righty backhand -- but in the Australian Open final, Federer's backhand was difference. The conviction behind it was different.

Standing inside the baseline in Melbourne -- thus hitting the ball a good foot lower -- Federer often hammered that backhand, low and hard. Ultimately, it won him the match. It happened again in Indian Wells. What used to be a liability against Nadal is now a strength.

"By coming over my backhand on the return, from the get-go of the point, I can dominate points right away," Federer said in his on-set interview on Tennis Channel. "It's important to keep your opponent off-guard and know that he has to be careful."

Once again, the Federer backhand is trending -- and, quite possibly, better than ever. Who does he think he is, Stan Wawrinka? This is more evidence that the six-month sabbatical from competition was a decidedly good thing.

That turnaround can be traced back to Federer's decision three years ago to go to a larger Wilson racket head. Eight square inches might not seem like a lot, but when Federer abandoned his trusty 90-inch model and upgraded to a 98-inch version, it led to a little more thump, particularly on his weaker side, the backhand.

"I used to shank balls often with my older racket," Federer said. "But then again, it helped me a lot with my slice and my forehand. But with this racket, I have easier power, and I gain confidence. And once you have the confidence, you step in, and once you step in, then it's easier to pull back again."

Federer now matriculates to the final eight, in which the sizzling-hot Nick Kyrgios, who stunned No. 2 Novak Djokovic in straight sets earlier in the night, awaits. With the Serb and Nadal, along with Andy Murray, watching from the sideline, the four-time Indian Wells champion Federer looks like the player who will emerge from one of the most competitive sections of any draw we've seen in quite some time.

"I feel I am having a lot of fun on the court because I feel like I can play in a lot of different ways," Federer said. "Even though I could do that way back when as well, I am just able to step into the court much easier than I ever have."

The fact that Federer is again threatening to win a major event seems surreal. For a while there, he and Nadal looked a lot like has-beens.

In a three-year span from 2014 to '16, they won a single Grand Slam singles title between them, Nadal's 2014 victory at Roland Garros. Djokovic won a remarkable six majors in that span, followed by Stan Wawrinka with three and Murray and Marin Cilic with one each.

Then, with both Federer and Nadal returning from serious injuries at the dawn of the 2017 season, the two long-time rivals staged an out-of-the-blue renaissance, reaching the final in Melbourne. Federer, 35, won an epic, five-set match that changed the Grand Slam conversation on a number of levels.

It was his first major triumph in more than four years, and it raised his total to 18. Perhaps more significantly, it was an ominous signal to #NextGen that the old guys weren't quite finished.

Talking about the recent phenomenon of late bloomers, Federer opined that professional players are in their "best period" between ages 23 and 28. Seven years past that sweet spot, Federer is still challenging himself, still setting precedents.

Now, after four rounds at the BNP Paribas Open -- no, this wasn't a mirage in the California desert -- we have further confirmation.

Nadal still leads the 13-year rivalry with Federer 23-13, but Wednesday offered a new and telling wrinkle: Federer beat Nadal for the third straight time for the first time in his career. That's right: the 2015 Basel final, this year's Aussie Open final and Wednesday at Indian Wells.

After all these years, his first hat trick.