Andrey Rublev will meet his fellow Russian and close friend Daniil Medvedev in the quarter-finals of the Australian Open after Casper Ruud was forced to retire from their last-16 encounter on Monday.
Rublev had won the first 6-2 and led by a break in the second send when Ruud called for treatment on what appears to be an abdominal issue. The Norwegian soldiered on manfully, forcing the seventh seed to a tiebreaker, which Rublev duly won 7-3.
But before they could begin the third, Ruud announced that he was throwing in the towel and his injury had got the best of him.
'I wasn't good enough' - Murray after Rublev defeat in Rotterdam
Highlights: Ruud forced to retire as Rublev wins through
"I feel sorry for Casper," said 23-year-old Rublev. "I hope he recovers real quick. I did not expect it to end this way, but this is sport.
""I'm feeling perfect. "I'm feeling physically great."
On the prospect of playing Medvedev, Ruud is excited by the chance to avenge his loss to his compatriot at last year's US Open and record his first career win over the 24-year-old.
"At least one of us will be in semis, that's good news," said Rublev, who was leading 6-2 7-6(3) when Ruud called it quits.
"Last time he beat me in the quarter-final of the US Open and now we meet in the quarter-finals of Australian Open, we'll see what happens.
"I hope we can show great level and it will be a great battle."
Murray beaten by Rublev at Rotterdam Open
Murray tips Rublev for long period at the top