Daniil Medvedev won the all-Russian clash at the US Open to deal his friend Andrey Rublev more quarter-final misery.Third seed Medvedev, the 2021 champion at Flushing Meadows, lost the opening three games of the match as Rublev flew out of the blocks.The world number eight, who is godfather to Medvedev's daughter, won the first eight points and 14 out of the first 15.But Medvedev quickly grew into the match, winning the first two sets amid some punishing rallies in stifling heat inside Arthur Ashe Stadium.Rublev led by a break in the third but was pegged back again, and in a 15-minute final game, Medvedev converted match point at the fifth attempt to wrap up a 6-4 6-3 6-4 victory.Luckless Rublev has now made the quarter-final stage in nine grand slams, and he has lost all of them."It was brutal," said Medvedev. "The only good thing is in these conditions both suffer."I know he never gives up, but he knows I never give up too."