World No.1 Rafa Nadal has given Russian teenager Andrey Rublev a tennis lesson to race into the semi-finals of the US Open and a possible showdown with Roger Federer.

The 19-year-old, who grew up idolising Nadal and had the Spaniard’s poster pinned up on his bedroom wall was smiling from ear-to-ear as he posed for pre-match photos with his hero.

That would be the highlight of an eye-opening afternoon for the Russian youngster as Nadal showed no mercy during a one hour, 37 minute thrashing.

“I knew a great new generation coming and Andrey is one of these players that have a great future and I wish him all the best,” Nadal said, after clinching his spot in his 26th grand slam semi-final.

“It was a good match and obviously it was Andrey’s first quarter-finals and of course he played with some more mistakes than usual, but for me it was an important victory winning the last two matches in straight sets.”

While fans were still filing into Arthur Ashe Stadium, Nadal was wrapping up a clinical first set in 23 minutes.

Rublev offered some resistance to start the second but it was brief, Nadal breaking to go up 3-2 and again to close out the set.

A relentless Nadal broke to open the third and when Rublev double-faulted to hand him yet another break at 4-1, the dejected Russian simply bent over and let his racquet drop. 

Andrey Rublev grew up idolising Nada. Photo: Getty

But Rublev was not done scolding himself, dropping into his chair during the changeover then hammering away at his foot with his racquet.

Up next for Nadal will be the winner of the quarter-final clash between five-times US Open champion Federer and Juan Martin del Potro, the 2009 winner.

If Federer can get past the towering Argentine it would set up a landmark meeting with the Swiss and Nadal never having previously met at Flushing Meadows during their 37-match rivalry.

“It is something a little bit strange that we never played here because we played a lot of times in all the important events around the world so it is something we missed,” Nadal said.

“It would be much more special if it could happen in the final but we’re going to come back and try to make that happen.”