Stefanos Tsitsipas, one of the brightest stars on the ATP tour, is enjoying a breakthrough week in Barcelona. The 19-year-old Greek has upset three seeds, including Dominic Thiem, on his way to the ATP 500 semifinals. 

Tsitsipas, currently ranked No. 63, also knocked out the No. 7 and No. 10 seeds, Diego Schwartzman and Albert Ramos-Vinolas—both in straight sets.

The 2018 season has been a breakout year for Tsitsipas, reaching his first ATP 500 quarterfinal in Dubai in February.

Tsitsipas is relatively new to the tour, and shared a scary near-drowning experience with the ATP. He says his whole perspective on life changed after it, and it's something that's actually helped his career.

He's guaranteed to rise to a career-high ranking of at least No. 51.

This week on Tennis Channel Plus: 

ATP Barcelona Outer Courts (4/23-4/26)
-Catch all the action from Barcelona with outer-court coverage live on Tennis Channel Plus beginning Monday April 23 at 5 a.m. ET