Medvedev works graveyard shift to reach last 16

Third seed Daniil Medvedev worked the U.S. Open graveyard shift again on Saturday 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 p.m. ET (0300 GMT) 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.

"It felt like we were both playing well in the first two sets and I was just a little better on the important points," said Medvedev. "Everything was going my way and in the third set he raised his level just a little bit, and it was enough to make the match even tougher.

"Lucky and good for me to stay in the third set and not finish at four."

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.