In case you were wondering, Rafael Nadal is still the master of clay

Rafael Nadal gave up just nine games as he crushed No. 4-ranked wunderkind Alexander Zverev on Sunday to engineer Spain's successful turnaround in its quarterfinal Davis Cup win against Germany.

Nadal sent a strong statement, if that wasn't already obvious. This was just his second match since a hip injury forced him to quit in the middle of his Australian Open quarterfinal against Marin Cilic. Nadal's first match, last Friday, at Davis Cup was an equally persuasive win over a lesser light, 34-year-old German veteran Philipp Kohlschreiber.

"It's a great feeling," Nadal said after he demolished Kohlschreiber. "Coming back from injuries is always difficult, but it's great to be in front of my crowd on a very memorable day."

The 31-year-old, No. 1-ranked Nadal manhandled Zverev, 20, on the slow red clay in Valencia in just 2 hours, 16 minutes. A point worth making, because some were puzzled, and others disgruntled, when Nadal took over the No. 1 ranking from Roger Federer last Monday -- while still inactive.

That wasn't a computer glitch or the handiwork of some Nadal-obsessed hacker. Federer was unable to defend the champion's rankings points he earned by winning at Indian Wells and Miami last year. The decline in his 12-month points total was enough to elevate Nadal, who showed he was more than up to the honor.

Nadal looked formidable in Valencia. He used his serve superbly, placing it rather than banging it, as if he were playing darts rather than home run derby. All the familiar, ritualistic ticks were there. Before serving, Nadal tugged at his shorts, then, using the fingertips of his right hand, he grazed in rapid succession his left shoulder, right shoulder, eyebrow, ear, nose and hair. He wiped and flicked away a bead of perspiration from his brow.

Nadal was working, make no mistake. That devastating one-two punch of his sliding, wide serve to the backhand in the ad court, backed by an inside-out forehand winner, won numerous points. Body flexing backward as he belted a forehand, it seemed like he was hitting a heavy object, perhaps a medicine ball. He was quick and resourceful around the net, unafraid to switch from forehand blast to delicate drop shot mid-swing. As usual, Nadal always got that one more ball back over the net to claim points he appeared to have lost.

Here's another statement: The heebee jeebees are gone for good.

Nadal lost confidence during his slump of 2014-15. He was often prone to anxiety as he struggled to reassert himself in 2016, but it set the stage for his spectacular 2017. Any question of backsliding in the nerve department was laid to rest in Valencia. His resolve was steady, his hand firm.

The most diehard of Nadal fans couldn't have asked for a more auspicious return, but the future may not be quite as clear as the weekend suggested. After the Zverev match, a British interviewer asked Nadal if he was "pain free."

Nadal grimaced at the question and replied, "That's difficult [to say], but I am playing with no limitations."

You can forgive Nadal for not entirely trusting his body; he's put on lots of miles over the years. Some of his injuries seemed to come out of the blue, including the most recent one. One minute he's battling Cilic tooth and nail, then a slight tweak in a leg and -- bingo -- he's up at the net, wishing Cilic good luck in the Aussie semifinals.

In the coming weeks, Nadal will face the same challenge that laid low his rival Federer during the U.S. hard-court swing. He must defend a nearly perfect record. Last year, Nadal won three titles and put together a 17-match clay-court winning streak before Dominic Thiem throttled him in Rome. Nadal bounced back and capped the clay season with another triumph at the French Open. In order to maintain his ranking, he will have to come close to duplicating those results.

But if anybody can go undefeated through an entire calendar segment featuring one Grand Slam and three Masters 1000 events, it's Rafael Nadal.