Daniil Medvedev will play Russian compatriot and close friend Andrey Rublev in the US Open quarter-finals after defeating Australian 13th seed Alex de Minaur in four sets on Monday.
Third seed Medvedev fought back from a set down to brush De Minaur aside 2-6, 6-4, 6-1, 6-2 as he bids to add a second US Open crown following his maiden Grand Slam title in New York two years ago.
"The conditions were some of the most brutal we’ve ever played," Medvedev said of the hot and humid conditions in Louis Armstrong Stadium.
"There was one moment where I thought I'm not going to be able to play until the end, it's so tough.
"But I looked across the net and noticed he was slowing down too, so I thought okay, I can do this."
The 27-year-old Medvedev, a winner of four hard-court titles this season, is through to the last eight of the US Open for the fourth time in five years.
He beat Rublev in straight sets at the same stage of the tournament in 2020 and holds a 5-2 record over his friend who is the godfather of his daughter Alisa, born in October last year.
"We're really close friends," said Medvedev. "Even if on the court we're big competitors... I think nothing is going to come between us to separate us in real life.
"We're really close. I mean, we share a lot of let's call it interests and stuff like this.
"It's great to have someone like this on tour because sometimes can be not easy. You travel, travel, travel. To have a friend like this is great."
Despite their close bond, Medvedev is eager to once more thwart Rublev who lost in each of his past eight Grand Slam quarter-final appearances.
"But again, on the court we both want to win. We not going to be friends in two days."