Kyrgios going places fast Nick Kyrgios is aware of how much work lies ahead for him. It says something about Australian teenager Nick Kyrgios' grand slam debut at the French Open that world No. 10 Marin Cilic is wary of their second-round match-up on Wednesday. The 18-year-old, the world's top-ranked junior, caused a boilover with a straight-sets upset win over tough Czech veteran Radek Stepanek on Monday. The youngest player in the main draw, world No.262 Kyrgios only earned a wildcard at Roland Garros after the withdrawal of compatriot John Millman with injury. But he made the most of it in a 7-6 (7-4), 7-6 (10-8), 7-6 (13-11) win. He described the feeling of winning his first grand slam match as "10 times better" than his junior Australian Open triumph in January, but the big-serving teen has little time to reflect. After beating the world No.52, Kyrgios faces another steep rise in class against Cilic, of Croatia. The pair hit together during practice last week and Cilic, who also caught a glimpse of Kyrgios' victory, was clearly impressed. "He is going to be really motivated," said Cilic, who cruised past German Philipp Petzschner 6-1, 6-2, 6-3 on Monday. Stepanek is a difficult guy to play, so it shows he's really talented and dangerous. But Kyrgios was under no illusions about the difficulty of the task he faced. "He's obviously an unbelievable player," he said of his second-round opponent. He got to where he is playing world-class tennis. I just have to focus on what I have to do in the next couple of days. Refreshingly, though, Kyrgios spoke of how much work lay ahead. Asked why fewer players seemed to be breaking onto the tour at his age, he said: "To win a grand slam [match] you have to possibly play best of five sets every match. I've still got a long way to go physically. I'm obviously continuing to work on that every day. I guess it's obviously a lot of pressure as well. I was feeling that. The 2013 junior Australian Open champion has slashed his ranking by almost 600 spots since the start of the year and more than 1000 in the past year. He has chosen to base himself in the secondary locker room this week to avoid being star-struck by the likes of his idols Roger Federer and Rafael Nadal, and he still plans to play in the junior event. Kyrgios' junior coach and former professional, Todd Larkham, predicted the 18-year-old could crack the world's top 100 by the end of the year. To win against such an experienced player in your first grand slam, and to win all the close points ... shows that he's the real deal.