Q. You seemed to be really struggling towards the end there. Can you tell us about some of the aches and pains you had by that point in the match?
JUAN MARTIN DEL POTRO: Yes, I was feeling pain in all my body, but I just did my best. We played a good match. Andy, is a very good performance and in good shape. So he's the best winner. I'm happy.

Q. You had a lot to say to each other at the net at the end. Can you give us some idea of what was being said.
JUAN MARTIN DEL POTRO: All I said congratulations, good luck for the next match. He played an unbelievable match. We played like four hours, I don't know. But he's a great player. And that's it.


Q. You came into the match, you've won many, many matches in a row, very strong tennis. Can you look back at the tournament and feel quite successful with your performance here?
JUAN MARTIN DEL POTRO: No, I don't know. I improve a lot. That's the point for my success.
But today I play against one of the best player of the world. He beat Nadal the best player of the world, and he beat Djokovic in Cincinnati, he beat everyone. I did my best. He won a good match, and he's in semifinals.
But I want to work hard because in the fourth set I feel tired, and he was gooder than me, so I have to work.

Q. He didn't want to give you any pace, did he? Was that quite frustrating that he was constantly slicing the backhand and just asking you to put the pace on the ball?
JUAN MARTIN DEL POTRO: He did everything. I run a lot and I don't serve too good, but I play good behind the line.
We did good match. The people enjoy the match. He's more happy than me, but I'm not sad, you know.


(FastScripts by ASAP Sports via US Open, photo/AP Photo/Ed Betz)

Juan Martin del Potro - US Open 03. September Interview