'I'm still a little bit immature' - Shelton working to overcome mental hurdles and be a consistent winner on ATP Tour

Yeah, it felt great. To be honest, I was really happy with my return game. The way that I played from the ground from point one, for me, is where I want to be at. I think that the level that I maintained throughout the match was really high. And if I was nitpicky at all, it's just the way that I served at the end. I kind of lost the rhythm on my first serve. But I'm super happy with the way that I played tonight, the performance that I came up with. And I hope to continue to build on these things in the semis. I think being consistent. My habits, my routines throughout the tournament, the way that I stay focused, what I do with my off days, the way I prepare for my matches and continue to take care of my body, I think is really important. And being sharp mentally and physically is super important down the stretch in these tournaments. And something I'm still a little bit immature with at times, but definitely doing a lot better.