My back totally seized up on Saturday evening; I couldn't walk and it felt like someone was sticking a knife in my back.

I played aggressively and took my chances. I guess most importantly I felt physically good out on court.

But I do like the way I responded from that. I just played another good service game and just felt all round it was a good performance.

I felt like I wanted to be very meticulous and disciplined with my service games, and I think I did a very good job with that,