World number one Jannik Sinner produced some of his best tennis of the US Open so far to beat Tommy Paul and set up a tantalising quarter-final against Daniil Medvedev.

Italy’s Sinner beat home hope Paul 7-6 (7-3) 7-6 (7-5) 6-1 in front of a rowdy New York crowd in the night session on Arthur Ashe.

Russia’s Medvedev, the 2021 US Open champion, sent an emphatic statement earlier on Monday with a 6-0 6-1 6-3 win over Nuno Borges of Portugal.

The pair are the only Grand Slam champions remaining in an open men’s singles draw.

Sinner came back from two sets down against Medvedev to clinch the Australian Open title in January.

He has won five of his past six meetings against Medvedev, having lost six in a row previously, but Medvedev won their five-set Wimbledon quarter-final in July.

Sinner grew into the match against Paul, with his forehand initially leaking errors before the 23-year-old started to outmuscle his opponent from the baseline.

He trailed 14th seed Paul by a double break in the first set before reeling off three games in a row and dominating the resulting tie-break.

The second set was similarly close, but an early break in the third set Sinner up to close out victory in two hours and 42 minutes.

The only slight concern for Sinner was when he stumbled in a rally and clutched his hip – a problem he has struggled with throughout the year.

“There’s going to be a lot of rallies so hopefully I’ll be ready physically,” Sinner said of his match against Medvedev.

“We’ll try to do our best on court and hopefully you guys enjoy it.”

Sinner has lost just five matches this season, with two of those defeats coming on a hard court.

His most recent success was at Cincinnati in August, winning the title the day before news emerged he had been cleared of any wrongdoing after twice testing positive for a banned substance earlier this year.

It is the fifth time in the past six years that Medvedev has reached the last eight at Flushing Meadows.

The fifth seed was broken just once in the match, as he went down 2-1 in the third set, before play was delayed after a fire alarm went off in the building where the electronic line calling team is.

The US Open does not have line judges, with all the calls made by the Hawkeye technology.

The building was evacuated, leading to a brief pause in play, before fifth seed Medvedev immediately broke back and won five of the next six games to advance.

Medvedev was interviewed on court afterwards by Nick Kyrgios, who was the last player to beat him before the quarter-final stage in New York.

“The last time I lost in the fourth round was against you, right? Good memories,” the 28-year-old joked.

“I try to work hard. Sometimes I do, sometimes I don’t.

“I have the mentality that if the other guy practises more than me, I have less chances to win, and I want to win all the time.”

Britain’s Jack Draper earlier advanced with an impressive straight-sets victory over Tomas Machac to reach his first Grand Slam quarter-final.

He will play 10th seed Alex de Minaur in the next round after the Australian beat compatriot Jordan Thompson 6-0 3-6 6-3 7-5.

After De Minaur breezed through the opening set in just 29 minutes without losing a game, Thompson hit back to take the second and ensure the remainder of the match was far more closely contested.

De Minaur secured the win after a topsy-turvy fourth set to become the first Australian man since Leyton Hewitt in 2004 to reach three consecutive Grand Slam quarter-finals.