Mikael Ymer was first out of the Swedish duo when he was on track 12 in Flushing Meadows against Filip Krajinovic from Serbia.
But just over two hours later, the adventure was over for the 21-year-old Swede.
Ymer had to fight from the start against 26-seeded Krajinovic.
But after losing the first set clearly, by 2-6, he took command in the second.
Some serveess took him up in a 5-2 lead, but the Serb did not give up and managed to arrange a tiebreak, where he did not show any pardon and won 7-3.
Ymer, who in addition to his nine aces, had problems with the first serve during the match, then could not stand up.
2 hours and 15 minutes after the first ball of the match, Krajinovic was the winner via 6-2, 7-6, 6-3.
He will thus face the American Marcos Giron in the second round.
At the same time as the match ball was hit in Ymer's match, Rebecca Peterson kept even pace with the Belgian Kirsten Flipken's some path away.
The two players followed each other during the first set.
Peterson, who for the first time in his career was seeded in a grand slam tournament, managed to break the Belgian's serve, but Flipkens broke right back and the first set went to a tiebreak where Flipkens was the number bigger.
The second set continued where the first ended, evenly but with a small advantage for the Belgian.
Peterson had an early serve breakthrough against him and was forced to chase so as not to lose the match.
In the end, it didn't work out anymore and Flipkens won 7-6, 6-4.