Norway's Casper Ruud became the first singles player to reach the semi-finals of the US Open with victory over Matteo Berrettini, while Ons Jabeur progressed past Ajla Tomljanovic in straight sets.
Berrettini was made to pay for a woeful start at the Arthur Ashe Stadium, and despite clawing his way back into the match, Ruud secured a straightforward 6-1 6-4 7-5 [7-4] victory.
Ruud quickly brought up a double break point in Berrettini's first service game, where a mishit forehand from the Italian handed his counterpart a 2-0 lead before he ceded another break with a whimper.
It took Ruud under half an hour to wrap up the first set, and an incredible through-the-legs shot helped the Norwegian break the error-strewn Berrettini early doors in the second set.
The Italian started a slow fightback after Ruud squandered two set points and managed to earn a break back of his own, but yet another mishit backhand shot saw a near-faultless Ruud go 2-0 up in the match.
However, Berrettini's comeback kicked up a gear not long after as he stormed into a 3-0 lead in the third set, but volleys bedevilled the 13th seed as Ruud began to threaten again at 4-5.
The fifth seed - who is aspiring to become world number one at Flushing Meadows - served well to force a tie-break, during which he brought up four match points and took the third to book his spot in the semi-finals, where he will meet either Nick Kyrgios or Karen Khachanov.
Wimbledon runner-up Ons Jabeur and Ajla Tomljanovic provided the day's next entertainment at Arthur Ashe, and the former created more history for Africa with a 6-4 7-6 [7-4] success to make the semi-finals, but not without her wobbly moments.
A pulsating first set saw Jabeur post well-hit winners and unforced errors in equal measure, but a pair of breaks helped her get over the line before she quickly went 2-0 up in the second set.
However, Tomljanovic was able to match the Tunisian break for break as Jabeur began to let her emotion show, with her box feeling the full force of her frustrations before Tomljanovic went 5-3 up.
The Australian's next service game was a truly forgettable affair, though, as Jabeur broke to love with a double fault from Tomljanovic doing the damage.
A tie-break would be required to settle the second set, where Tomljanovic's ninth double fault of the match allowed Jabeur to move into a 5-3 lead, and the Tunisian moved onto match point with an ace.
Despite experiencing her frustrations in the match, a stern-looking Jabeur raised a fist after Tomljanovic netted a backhand to confirm the former's place in the semi-finals and see her become the first-ever African to reach the final four at Flushing Meadows.
Jabeur will now meet either France's Caroline Garcia or home favourite Coco Gauff for a place in the final.
