Fifth-seeded Learner Tien prevailed in a tight all-United States semifinal match at the Next Gen ATP Finals, beating second-seeded Alex Michelsen 2-4, 4-2, 1-4, 4-0, 4-1 on Saturday in Jeddah, Saudi Arabia.

Tien advances to Sunday's championship match against eighth-seeded Joao Fonseca of Brazil, who eliminated sixth-seeded Luca Van Assche of France 4-2, 4-2, 4-1.

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 championship match features the top two players from the Blue Group in round-robin play earlier this week. Fonseca registered a 4-0, 4-0, 1-4, 4-2 victory over Tien on Thursday.

--Field Level Media