Kei Nishikori claims he is improving with every match he plays after securing a place in the quarter-finals of the New York Open.
The 28-year-old Japanese former world number four spent five months on the sidelines since last August because of a wrist problem and he is now working his way back to full fitness.
Nishikori went out at the first-round stage of his comeback at Newport each last month, but responded well with victory at an ATP Challenger Tour event in Dallas.
And he is now making serious inroads in the New York Open with Wednesday's 6-2 6-4 win against Russia's Evgeny Donskoy taking just 65 minutes to complete.
Nishikori, who will next face Moldova's Radu Albot, told the ATP website: 'I served really well, especially in the second set. I started getting my rhythm back and my first serve was working really well but also everything else was pretty solid today.
'I was playing aggressive and coming in. Every match is improving. So far so good. I think today was one of the best again.'