"I'm so glad to be part of this amazing tournament. I have good memories from being here in 2009. I'm trying to play my best tennis. I'm really enjoying this week," BBC Sport quotes him as saying.
"It's not easy to win a set 6-0. Janko was fighting. He's a very good player. I have a high step up against Federer on Saturday but I will try to beat him.
"I have worked a lot every day to be here [after my injury problems]. I made a good comeback last year. I'm back in the top 10. I really want to enjoy this week."
Del Potro will take on world number two Roger Federer on Saturday.