MILAN (AP) Italian teenager Jannik Sinner became the first player to reach the semifinals of the Next Gen Finals in Milan as he eased to a dominant victory over Mikael Ymer on Wednesday.

The 18-year-old Sinner, who is the youngest player inside the Top 100, won 4-0, 4-2, 4-1 in his second match at the round-robin event, which features a unique format where each set is first to four games.

In the other Group B match, second-seeded Frances Tiafoe of the United States - who lost to Sinner on Tuesday - beat Ugo Humbert of France 4-2, 4-3 (5), 3-4 (4), 4-1.

Top-seeded Alex de Minaur of Australia, who was runner-up last year, leads Group A after defeating Miomir Kecmanovic of Serbia 4-1, 4-3 (4) 1-4, 4-0 to make it two wins out of two.

Kecmanovic is 1-0 in the tournament as is Norwegian Casper Ruud, who beat Alejandro Davidovich Fokina of Spain 3-4 (2), 4-3 (2), 4-2, 3-4 (2), 4-1.

This is the third edition of the year-end event for the best under-21 players.