Third seed Daniil Medvedev was on court in to the early hours again on Saturday night beating in-form Sebastian Baez 6-2 6-2 7-6(6) to end the Argentine's 12-match winning streak and ease into the fourth round of the season's final Grand Slam.
It was the second straight match that Medvedev started a contest one day and finished the next, having gone four sets with Australian Christopher O'Connell in a late night battle on Thursday that wrapped early Friday morning.
"Tough, I just want to go sleep, that's it, nothing more," Medvedev told the crowd that stayed to watch the match through to its conclusion.
In a match that got underway just before 11.00 pm ET (7.00 am GST) Medvedev went right to work breaking Baez twice to jump out to a 4-1 lead on the way to taking the opening set.
Playing as if he was trying to end the contest before the clock struck midnight, Medvedev broke Baez again to open the second, racing to a 2-0 lead but Baez was not interested in a quick finish, building a 5-2 advantage in the third when the contest was stopped to allow the roof to be closed as rain began to fall.
When play resumed Medvedev, who had been growing increasingly agitated, came out with new focus, breaking the Argentine to get back on serve 5-4 and forcing the set to tie-break he would win 8-6.
The win set up Medvedev for an intriguing last 16 meeting with Australian danger man Alex de Minaur.
Medvedev and de Minaur have met six times with the Russian winning four but the Australian has won the last two, including a quarter-final clash at last month's Canadian Open.
Daniil Medvedev is worried how one fan is going to sleep tonight.— US Open Tennis (@usopen) September 3, 2023
This soundbite is an all-timer. pic.twitter.com/B9YsAty4Ws