“There isn’t much that separates No. 1 from No. 100.”

Every so often, you hear a version of that statement from a professional tennis player. Your reaction probably goes something like this: “Yeah, right.”

But this week in Doha, Rafael Nadal, the current world No. 1, seems to have set out to show us that there’s a kernel of truth to those words. First, Rafa was pushed to a 9-7 second-set tiebreaker by 47th-ranked Lukas Rosol. Then he dropped a set to 74th-ranked Tobias Kamke. Today, in the semifinals, Nadal outdid himself by surrendering the first set to a German qualifier by the name of Peter Gojowczyk, the world No. 162.

Gojowczyk, who upset No. 6 seed Philipp Kohlschreiber and survived a third-set tiebreaker against Dustin Brown in the quarterfinals, came out looking like a man ranked much higher. He broke Nadal in the second game and coasted to a 3-0 lead in a matter of minutes. Gojowcyzk’s serves found the T. His forehand, which he hits with an easy, flat motion, skidded through the court and caught Nadal off-guard. And his two-handed backhand, roped like a left-handed batter in baseball, left smoke trails in the corners of the court. Gojowyczk hit 10 winners to Nadal’s two in the first set, and broke for a second time to win it 6-4.

That's when it was time for another well-known tennis-player quote to take effect:

“At a certain point, a guy is going to show you why he’s ranked what he's ranked.”

This was a favorite line of Andy Roddick’s, but Nadal kept it in mind today. Asked afterward what he was thinking during the first set, Rafa said he was just hoping his opponent wouldn’t maintain his "unbelievable" level. Gojowczyk didn’t, of course, and Nadal didn't stay at his level, either. With a down-to-business look and a no-nonsense walk, Nadal broke right away in the second set and locked it up by breaking again for 4-0. Now Rafa was the one in charge of the rallies. He worked to hit more forehands and moved the German wide of the sidelines whenever he could. Over the last two sets, Nadal would hit 24 winners to Gojowczyk’s four.

To his credit, though, Gojo didn’t just go. Broken to start the third, he broke back in the next game, and he used his serve well enough to stay within one break until the final game. But by the end, Nadal’s level was too high, and he was using the whole court with confidence. At 2-1, he held with a forehand drop-volley winner and then a backhand overhead winner. At 3-2, he held with three well-shredded forehand winners, hit viciously enough that Eurosport commentator Frew McMillan accused Rafa of “having no compassion for the ball.” And at 5-3, Nadal broke at love with one more forehand winner up the line.

With his 4-6, 6-2, 6-3 victory, Nadal moves on to the final in Doha, a tournament he has never won; he’ll face the winner of Florian Mayer and Gael Monfils. Rafa probably hopes he plays Mayer, because Monfils has recorded the only two wins of his career over Nadal on these courts, each time in straight sets.

It's true, there really isn’t much that separates No. 1 from No. 100, or No. 47, or No. 74, or even No. 162. It’s just that No. 1 is in the final, and those guys aren’t.