Marin Cilic, tennis' newest Grand Slam champion, says he was not enjoying the game as much in his efforts to return to the Top 10. With his title at the U.S. Open, the Croat is back to his career-high ranking of No. 9.

"I was swirling around ranking Top 20, 25, 15 and things were some days going well, some not. You are a lot of the time up and down," he said.

"It's, I feel, very inspirational for all the other guys out there who are, you know, working. I would definitely feel much stronger if I would see somebody like me accomplish things like this. It sort of came out of nowhere for me. Few things clicked in just right before tournament sort of. I felt great about them, and match after match I played really good tennis. These last three matches, everything was working perfectly."

Cilic went five sets with Gilles Simon in the fourth round and then did not drop a set the rest of the way, beating Tomas Berdych, Roger Federer, and Kei Nishikori in his last three matches. He says it "seems completely unreal to be called Grand Slam champion."

"I started to play absolutely unbelievable starting with the fifth set with Simon. After that I had unbelievable run of the matches against these top guys. And what it means to me, it means everything. It's just a huge accomplishment and huge moment for myself and for my team and for everybody around me who was with me all these years supporting me, believing in me and never giving up. So this is just the peak of the world."