JEDDAH, Saudi Arabia (AFP) — Learner Tien set-up an all-American Last-Four clash against close friend Alex Michelsen in the NextGen ATP Finals on Friday by knocking out top seed and 2023 runner-up Arthur Fils.

The 19-year-old Tien, who has risen to 122 in the world after starting the year at a lowly 453, shocked his 20th-ranked French opponent 4-2, 4-2, 3-4 (4/7), 4-3 (7/5).

“I thought I played really well today. It was great to rebound and have a good match after getting chopped by Joao Fonseca yesterday,” said Tien who avenged a loss to Fils in the first round of the US Open in August.

Michelsen wrapped up his group commitments with a third successive victory when China’s Shang Juncheng retired from their clash in the second set.

He then watched Tien defeat Fils from the player’s box, turning around and pointing at the back of his sweatshirt, which read “Victory Royale” — a phrase used in the video game Fortnite when a player is the last one standing.

“We play Fortnite a lot together, so it’s kind of a joke,” Tien explained.

“Our agent got us tracksuits that say that on the back. We both got different colors.”

France’s Luca Van Assche claimed the remaining semi-final spot by seeing off Nishesh Basavareddy of the United States 3-4 (2/7), 4-3 (9/7), 4-2, 4-2.

Van Assche will face Brazilian 18-year-old Fonseca, the lowest ranked player in the eight-man tournament, in Saturday’s semifinals.

“It was very, very close. I think I played at a good level. The start was tough but then I managed to play better,” Van Assche said.

“I managed my emotions well, especially when my head was exploding. I like to thank the public here because it was busy and they were cheering for me a lot. I am ready for the semifinals.”

Fonesca went 3-0 in the group stages by seeing off third-seed Jakub Mensik in five sets.