Alexander Blockx is the most credentialed Belgian prospect to arrive since David Goffin, an Antwerp-born right-hander who built his case in juniors before grinding the slow route through the Challenger ranks. Born in April 2005, he established himself on the junior circuit — including winning the 2023 Australian Open boys' singles title — then transitioned into the professional ranks. That junior crown, taken over Learner Tien in a three-set final, made him the first Belgian boy to win a junior Grand Slam since Kimmer Coppejans at Roland Garros in 2012. He turned pro in 2022 and has worked with longtime coach Philippe Cassiers since childhood.
The frame is size plus a clean strike. At 6'4", his height is one of the biggest assets in his game, especially on serve, where he generates considerable power and angle. Behind a two-handed backhand, he's a hard-court product by volume — all six of his Challenger/ITF titles came on hard — but the breakthrough numbers have come on dirt, where his clean ball-striking and movement translate.
The defining run came on clay in May 2026. After advancing to his first Masters 1000 semifinal at Madrid, he beat No. 5 Félix Auger-Aliassime and defending champion Casper Ruud to become the third Belgian Masters 1000 semifinalist after Goffin and Christophe Rochus since the series began in 1990. He had already qualified for the 2025 Next Gen ATP Finals and reached the final, losing to Tien in a rematch of that junior Melbourne title bout.
The current beat is a top-40 player still finding his ceiling. His career-high No. 36 came on 4 May 2026, making him the No. 1 Belgian in the ATP rankings. At the French Open he reached the second round on debut with a straight-sets win over Coleman Wong, then withdrew with an ankle injury ahead of a meeting with Alex de Minaur. The grass swing is the open question — the surface where his record is thinnest.