Images from the men's singles Round of 16 matches at the US Open on Monday.

Top seed Jannik Sinner survived a hard-fought battle against Tommy Paul to beat the American 7-6(3), 7-6(5), 6-1 and reach the US Open quarter-finals on Monday.

Sinner, who fired down 10 aces at a rocking Arthur Ashe Stadium, became the only man to reach the last eight at all four majors this year.

He next plays 2021 champion Daniil Medvedev in a rematch of their Australian Open final this year, which the Italian won in a five-set thriller.

"Tough match. It's going to be a lot of rallies so hopefully I'll be ready physically," said Sinner.

Paul, backed by a boisterous home crowd, produced some of his best tennis and defended 10 of the 14 break points he faced, but his hopes of ending a 21-year U.S. drought in the men's Grand Slams were snuffed out by Sinner's precision play.

Paul raised American hopes when he won 11 consecutive points to go up 4-1 in the first set but Sinner retaliated quickly, converting a break point chance in the sixth game and again in the eighth with a wicked forehand winner down the line.

Sinner had a chance to close out the set in the 10th game but could not convert a break point and the crowd broke into chants of "USA!" during a tense tiebreak, where the Italian forced Paul into a backhand error on set point.

Sinner let a break point chance slip through his fingers late in the second set and the umpire had to calm the crowd repeatedly in the tiebreak, as the Italian subdued his opponent from the baseline.

Paul survived a 21-shot rally to save break point in the second game of the third set but a double fault gave Sinner another chance and the world number one converted, whipping a forehand winner past the American.

Sinner pumped his fist with satisfaction after Paul sent a shot long on match point.

"I served very well in the beginning of the match and yes there are some ups and downs obviously," said Sinner.

"Finding my rhythm at the end of the match hopefully helps for the next match."

Medvedev trounces Borges

Daniil Medvedev barely broke a sweat as he brushed aside unseeded Nuno Borges 6-0, 6-1, 6-3 to advance to the quarter-finals of the US Open with an utterly dominant display at Arthur Ashe Stadium on Monday.

Fifth seed Medvedev is the only former champion left in the men's draw and the clash was a one-sided contest where Borges, playing in a Grand Slam fourth round for only the second time in his career, had no answers to the Russian's power.

The manner of the victory was a far cry from the same stage at the Australian Open where Borges managed to take a set off Medvedev but here he made 10 double faults and 51 unforced errors.

"To be honest, he played worse (than in Melbourne)," Medvedev told reporters. "Even by the stats he made a lot of unforced errors, a lot of double faults. Everyone is doing double faults here, probably something to do with condition of the balls.

"Especially in some games, it was maybe two or three so this gives you an easy break. I managed again to serve much better than the days before, so I didn't give him this opportunity to break back. It's a little bit of extra pressure."

Medvedev, the 2021 champion, whitewashed Borges in the opening set, toying with the Portuguese who was no match for the towering Russian's powerful baseline returns and his movement at the net.

Medvedev lost only 11 points in the opening set but Borges finally got on the board in the second set, earning a round of applause as he went 1-0 up.

But the rest of the set was more of the same as Borges made several unforced errors and Medvedev took a two-set lead.

The crowd did get behind Borges, who briefly flipped the script and took the lead in the third set.

But a fire alarm led to a brief pause in play which gave the Russian time to recover and he won five of the next six games to wrap up the contest.

"Strange experience but it did help me because the next two points I felt like he started to get the momentum and this broke it a little bit," Medvedev said.

Draper makes first Grand Slam quarter-final

Britain's Jack Draper crushed an error-prone Tomas Machac 6-3, 6-1, 6-2 to reach the quarters of a Grand Slam for the first time.

The 25th seed has won all 12 sets he has played at Flushing Meadows this year and awaits the winner of an all-Australian battle between Alex de Minaur and Jordan Thompson.

Coming into the Round 4 match, the No. 25 seed had yet to drop a set at the 2024 US Open and lost his serve just once. 

The 22-year-old Draper becomes the first Brit to make the quarter-finals of the men's singles at Flushing Meadows since Andy Murray in 2016.

Machac had won the three previous matches between the two but, after a strong start, was outclassed by a laser-focused Draper in an  hour and 44 minutes.

With a number of big names, most notably Novak Djokovic and Carlos Alcaraz, having gone out early, Draper has every reason to believe he can go all the way.

This was a statement performance in what has been a breakthrough year for the 6ft 4in left-hander, one that has included his maiden ATP title in Stuttgart and victory over Wimbledon champion Alcaraz at Queen's.

Should Draper win his quarter-final tie, he could face world number one Jannik Sinner in the last four.