If you want a glance at the next rising teenager in men’s tennis, look no further than 17-year-old Croatian Borna Coric. He made a name for himself on the junior circuit just last year, reaching the semifinals at both the Australian and French Opens and defeating Thanasi Kokkinakis (another future top player, most likely) in the US Open Junior final.

This year, though, still just 17, Coric has begun to make a name for himself on the ATP World Tour. He has competed mostly at the Challenger level this year after winning five Futures titles in 2013, but it has been his forays into top-level play were he has really shown that he is ready to join the main circuit—and soon.

In April, in a Davis Cup Group 1 tie against Poland, Coric was slated to face Jerzy Janowicz. HIs ranking was barely in the top 300, while Janowicz was a top-30 player. To be totally objective, Janowicz’s level of play in that five-set match was dismal. Still, Coric hung in there for hours against the much more powerful and much more experienced Pole. Coric won the match, and Croatia won the tie, in what was presumably only the first portent for things to come in his young career.

Coric was just granted a wild car into the 250-level tournament in Umag last week, where he displayed a performance that certainly grabbed him fans all over his country and probably should keep him in the eyes of the rest of the tennis world. He dominated his first-round match against top-50 player Edouard Roger-Vasselin and backed it up with another impressive straight-sets win over Horacio Zeballos.

Where Coric really showed what he was made of, though, was against top seed and world No. 20 Fabio Fognini in his first-ever Tour-level quarterfinal. Fognini seemed a little surprised at how well Coric played, but that should do nothing to diminish from the youngster’s performance. It was a tight battle throughout and was played at a high level from both players. Each pulled out remarkable shots at different times, although it was clear that Fognini’s experience and talent were just slightly superior throughout the final two sets.

What was most impressive, though, was that Coric was forced to play this match in the exact opposite way of how he had played against Janowicz in April. That Davis Cup rubber was on a hard court, and Coric had to play excellent defense, outlasting the big Pole until Janowicz would hit an error. Janowicz hit plenty of shots that would usually be winners, but Coric kept on staying in points and let his inconsistent opponent make mistake after mistake.

Against Fognini, though, the inverse was happening. Fabio’s defense on the slow clay court was astounding. Coric would hit big shot after big shot, but Fognini kept on sending them back deep. Point after point developed into protracted rallies, where Coric more than held his own. He hit some outstanding winners that left Fognini dumbfounded. Ultimately it was not enough, and Coric began cramping in the final two games, but it showed incredible potential. The performance also moved Coric into the top 200, which means that he should get in directly to any Challenger he wants and can probably get into qualifying for any 250-level tournament.

Coric is competing in the Cortina Challenger this week, preferring to stay on clay for this part of the summer at least. It does not look like he plans on switching to hard courts until the US Open qualifiers, but we know he can compete on the surface because he won last year’s junior US Open. We may not see Coric fully competitive on the main tour until next February, where presumably he will try to compete in the South American clay swing, but it should not come as a surprise to anyone if he is making headlines as early as this September.