No. 8 seed Joao Fonseca of Brazil improved to 2-0 and advanced to the semifinals of the Next Gen ATP Finals with a 4-0, 4-0, 1-4, 4-2 victory Thursday over No. 5 seed Learner Tien of the United States at Jeddah, Saudi Arabia.

The event includes the eight highest-ranked ATP Tour players age 20 and younger. Matches are best-of-five sets to four games, with a tiebreaker played if a set goes to 3-3.

The players are divided into two groups for round-robin play, with the top two from each group advancing to the semifinals.

After losing to Fonseca in a Blue Group opener Wednesday, No. 1 seed Arthur Fils of France earned a 4-2, 4-3 (4), 4-2 victory over No. 3 seed Jakub Mensik of the Czech Republic.

In Red Group play, No. 2 seed Alex Michelsen of the United States earned a 1-4, 4-2, 4-3 (6), 4-3 (5) victory over Luca Van Assche of France, while No. 7 seed Nishesh Basavareddy of the United States earned a 3-4 (4), 4-2, 4-2, 4-1 victory over Shang Juncheng of China.

Tien and Fils are now 1-1 in the Blue Group, while Mensik is 0-2. In the Red Group, Michelsen improved to 2-0 to advance to the semifinals, while Van Assche and Basavareddy are now 1-1 and Juncheng fell to 0-2.