At the 2026 US Open, Alexander Blockx defeated Francisco Cerundolo to become the first Belgian man to ever reach the quarterfinals at Flushing Meadows.
At 6-foot-4 tall and stringbean-thin, Alexander Blockx played the US Open Boys’ tournament in 2022 and reached the quarterfinals.
“Back then my body was quite fragile,” Blockx, who was a No.1-ranked junior, recalls. “We tried not to overpush it too much.”
The days of holding back are over, he says. These days Blockx darts around the court like a whirling dervish, challenging 2021 champion Daniil Medvedev for “fastest big man in tennis” bragging rights.
“I feel like two or three years ago, we started to really work on the physical side,” he told USOpen.org. “Right now, I can’t complain. I feel great. I think I’m quite fast on the court and my balance is there. Now it’s just about maintaining that physique.”
What history did Blockx make at the US Open?
Four years after his lone US Open junior appearance, Blockx is putting his physicality to good use as a pro on the gritty hard courts of the USTA Billie Jean King National Tennis Center.
On Sunday in his first-ever match in Arthur Ashe Stadium, the Antwerp native defeated Francisco Cerundolo, 6-3, 4-6, 7-5, 7-5 to reach the quarterfinals in his US Open debut. Making the result even more special is the fact that Blockx is the first Belgian man to ever reach the last eight at Flushing Meadows.
It gets better.
At 21, he’s also the youngest Belgian to reach a Grand Slam quarterfinal in the Open Era.
“It was unreal, to be honest,” Blockx said of his first experience in Ashe, on court after his win. “This morning, I stepped onto this court for the first time to warm up, and that felt unreal already. So playing a match here and winning a match here is even crazier.”
His rise from outside the Top 100 in February to inside the Top 30 (currently No. 26 in the ATP live rankings) is even crazier than that.
What was Blockx’s best result prior to the US Open?
Blockx, who has made his debut at all four majors this year (he won one match across the first three), turned heads this May in Madrid when he reached the semifinals in his fifth appearance at that level.
When the season started, did Blockx have this type of success in mind? Yes, and no, he said.
“Of course, you never think that, but you somewhat expect it at some point because of the work you put in,” he said. “With me, it happened this year...I was also thinking, if not this year, then next year or the year after. I’m still young. I have time. Of course, I wanted it to happen as quickly as possible.
“I think it definitely happened faster than I expected.”
Watching Blockx patrol his baseline at the Open, it’s easy to see why he’s enjoying a meteoric rise up the rankings. He’s powerful, precise and lightning-quick around the court. He’s usually on offense, making life miserable for his opponents with a scorching arsenal of groundstrokes, but when the situation calls for it, he puts his tree-trunk legs in action and blankets the court with impressive ease.
If he can be this good in his first appearance in Flushing Meadows, just think how good Blockx can be down the road, when a little more experience is peppered into his game.
“I feel like it’s all just getting started for me,” said the Belgian, who will face Learner Tien or Karen Khachanov in the quarterfinals. “I think I still have so many things to improve, and our team also knows it. We’re trying—even during tournaments—not to waste time and to keep improving a lot of things.
“I think I’m still far from my best level.”
