Sebastian Baez stepped up and delivered on the biggest stage Thursday at the Intesa Sanpaolo Next Gen ATP Finals as he became the first South American to reach the semi-finals in the tournament’s history.

The Argentine had never played a tour-level hard-court match before this week, but he downed Hugo Gaston 4-3(2), 4-2, 4-2 in 67 minutes to advance from Group B in Milan.

Baez held a 1-1 record going into his clash against the Frenchman, having beaten home favourite Lorenzo Musetti in his opening match, before he lost to Sebastian Korda on Wednesday.

With qualification on the line, Baez raised his level as he demonstrated great agility to chase down Gaston’s drop shots, while also opening his shoulders to hit through the World No. 67 to book his spot in the last four.

The 20-year-old hit 27 winners and broke Gaston four times en route to victory. Baez has enjoyed a standout 2021 season, capturing five ATP Challenger Tour titles, with all of his triumphs coming on clay.

The World No. 111 will learn whether he faces Group A winner Carlos Alcaraz or runner up Brandon Nakashima in the semi-finals following the conclusion of Korda’s match against Musetti later on Thursday. Both Korda and Musetti can still qualify, while recent Rolex Paris Masters quarter-finalist Gaston finishes the round-robin stage with a 0-3 record.