US Open 2026 pages
Sports · US Open 2026 · Men's Singles · Round of 16
Francisco Cerundolo vs 
Alexander Blockx
Round of 16
Watch: ESPN · ESPN2 · ABC · ESPN app
My pick: Francisco Cerundolo to advance · locked 2026-09-05 20:50 UTCPrediction
Neither of these two had reached the fourth round here before this week, and neither has been past it anywhere: the winner plays a first Grand Slam quarter-final. They have met once, in the Madrid round of 16 in April, and Blockx won it 7-6(8) 6-2 — on clay, during the week he beat Auger-Aliassime and Casper Ruud either side of it to reach a first Masters 1000 semi-final. Hard-court Elo has this at about 58-42 to the Argentine, and mostly on volume: 67-64 on hard against Blockx's 22-23, a season of 30-17 against 24-15, and seven years of tour-level matches against two. What complicates it is the state each arrives in. Cerundolo has just played three hours and forty minutes against Fritz on the back of a five-set win over Struff — nine sets and better than seven hours across two matches — and won today from two sets down while losing the points count 148 to 150. Blockx spent two hours forty-five putting away a fifth seed who was already spent, and did it with seventeen aces, 86% of his first-serve points and sixteen holds from eighteen. That serve is the thing likeliest to decide this: at 6'4" it is the one weapon on the court that does not care how tired anybody is, and Cerundolo's return has to be the answer to it. A rest day sits between here and Monday, which is what keeps this near the ratings rather than well past them. I take Cerundolo, shaded down for the mileage.
The case for Francisco Cerundolo
55% to winCerundolo is the more established player by a distance — five ATP titles, a Queen's Club championship this June, a career high of No. 18, and 67-64 on hard courts against an opponent barely above even at 22-23. Hard-court Elo has him 53 points clear. He has also just proved he can win a match he was losing: two sets down to the ninth seed on Ashe, 0-40 on his own serve at 3-4 in the fifth with Fritz two points from serving it out, and he took five straight points and the match. Whatever the mileage costs him, a player who has come from two sets down twice in his career has now done it in the biggest match of his life, and he gets a day to recover.
The case for Alexander Blockx
45% to winBlockx has beaten Cerundolo already, in Madrid in April, and did it in straight sets on the surface that should have suited the Argentine better. He is 21, he is Belgium's No. 1, and his ceiling this season is a Masters 1000 semi-final built on beating Auger-Aliassime, Cerundolo and the defending champion in the same week. Today he hit seventeen aces to five, won 86% of his first-serve points, held sixteen of eighteen and took 136 points to 91 against the fifth seed. He is also the fresher man by nearly five hours of tennis across the last two rounds, and at 6'4" his serve is the one shot in this match that a tired opponent cannot negotiate with.
Both cases written 2026-09-05, before the first ball — frozen into the record exactly as written, whatever the result. The percentages are mine — opinions with a percent sign on. They add to 100 because tennis has no draw to hide the rounding in.
Tale of the tape
Francisco CerundoloAlexander BlockxPlayer vitals: US Open official player feed (usopen.org) and Tennis Abstract career match logs · as of 2026-09-05.
Career head-to-head: Tennis Abstract career match logs (tour-level) · as of 2026-09-05.
The briefing
Storylines
- Neither man had reached the US Open fourth round before this week, and neither has ever been past a Grand Slam fourth round — the winner reaches a first major quarter-final.
- Blockx leads the head-to-head 1-0: the Madrid round of 16 in April, 7-6(8) 6-2 on clay, in the week he reached a first Masters 1000 semi-final.
- Cerundolo has played nine sets and better than seven hours in his last two matches; he beat Fritz from two sets down today while losing the points count 148 to 150.
- Blockx beat the fifth seed Flavio Cobolli with seventeen aces, 86% of his first-serve points and sixteen holds from eighteen.
- Alexander Zverev is the only top-ten player left in this half of the draw.
Head to head
One meeting, Blockx leading 1-0 — the Madrid round of 16 in April, 7-6(8) 6-2 on clay, during his run to a first Masters 1000 semi-final.
Source: Tennis Abstract career match logs (tour-level) · as of 2026-09-05.
Watch: Fourth-round coverage runs across ESPN, ESPN2 and ABC, with ESPN Deportes in Spanish — and every court streams in the ESPN app, which is where a match away from the two show courts will live. (ESPN press-room release and listings, as of 2026-08-27)
Court & schedule: Not yet assigned. The US Open posts each day's order of play the evening before, and this match has not reached the board yet. (Official US Open order-of-play release cadence, as of 2026-09-05)
Weather: Today stays sunny and 79°F, and then the rain comes back: showers tonight on a 36% chance at 67°F, and Sunday — the fourth round — at 72°F on 33%. Sunday night is mostly clear at 64°F, Labor Day is sunny and 77°F with nothing in it, and Tuesday is sunny at 79°F. Ashe and Armstrong close their roofs and play on; everything else waits. (National Weather Service New York forecast, as of 2026-09-05)
Venue: USTA Billie Jean King National Tennis Center, Flushing Meadows, New York — hard.
At this Stage
The Round of 16 is the fourth round, and the point at which a Grand Slam stops being a draw and becomes a tournament you can hold in your head: eight matches, played across Sunday and Monday, and the eight who come through are the quarter-finalists. Everyone still here has won three matches on these courts, so the seedings have stopped being a guide and the form of the fortnight has taken over.
