The second week of the 2018 U.S. Open gets under way on Monday at Flushing Meadows in New York, and two-time champion Novak Djokovic is in action at Arthur Ashe Stadium in the afternoon session.
The No. 6 seed faces a fourth-round clash with Portugal's Joao Sousa, who he has beaten in all four of their previous meetings without dropping a set.
America's Madison Keys kicks off the action at Arthur Ashe against Dominika Cibulkova in what should be a tight contest, while Kei Nishikori, Marin Cilic and David Goffin are all set to turn out at Louis Armstrong Stadium.
Here is the schedule for Monday afternoon, per the tournament's official website:
Arthur Ashe Stadium (Play begins noon ET, 5 p.m. BST)
(14) Madison Keys vs. (29) Dominika Cibulkova
(6) Novak Djokovic vs. Joao Sousa
Louis Armstrong Stadium (Play begins 11 a.m. ET, 4 p.m. BST)
(21) Kei Nishikori vs. Philipp Kohlschreiber
(26) Aryna Sabalenka vs. (20) Naomi Osaka
(7) Marin Cilic vs. (10) David Goffin
Djokovic, 31, triumphed in New York in 2011 and 2015 and has reached five other finals at Flushing Meadows.
Since 2007, he has reached at least the semi-finals every time he has competed at the U.S. Open.
He will confirm his place in this year's quarter-finals by beating Sousa, and there is little reason to suggest he won't continue his perfect record against the 29-year-old.
Sousa has never before made it to the fourth round at the U.S. Open, and he has played significantly more tennis at the 2018 tournament than Djokovic.
His four-set defeat of Lucas Pouille in the third round ran to three hours, 38 minutes, and he played for more than three hours against Pablo Carreno Busta in the second round.
It has not been plain sailing for Djokovic as he dropped sets in both of his opening rounds, but he has had an easier run of things than Sousa.
The Serb downed Richard Gasquet in three sets in the third round in a fine performance, per Metro's George Bellshaw:
George Bellshaw @BellshawGeorge
Djokovic: 'It was the best match of the week so far, without a doubt. One of the best performances I had in the hard court season after Wimbledon. I thought I was playing on a very high level from the first point. Very, very pleased with the performance.' Couldn't agree more.
Djokovic has struggled with injury in the last few seasons but is on his way back to his best, and his triumph at this year's Wimbledon moved him to 13 Grand Slam titles.
There seems an inevitability about him meeting Roger Federer at the U.S. Open, with the two superstars set to come together in the quarter-finals, assuming they both win on Monday.
No. 2 seed Federer takes on John Millman of Australia in the evening session on Monday, by which time Djokovic should have already sealed his place in the last eight.