JEDDAH: American Learner Tien overpowered Belgian opponent Alexander Blockx 4-3(4) 4-2 4-1 to win the Next Gen ATP Finals on Sunday, the year-ending exhibition tournament between the eight highest-ranked players on the tour aged 20 and under. The tournament uses a modified format, where a player needs to win four games to clinch a set, and winning one point at deuce is enough to take the game.