- Teenage upstarts Cici Bellis, ranked at 1,208, and Borna Coric, the men's number 204, made stunning Grand Slam debuts on Tuesday, rocking the sleepy US Open out of its early slumbers.
Wildcard Bellis, just 15, caused the biggest upset when she knocked out Australian Open runner-up, Dominika Cibulkova, the 12th seed, 6-1, 4-6, 6-4 to become the youngest player to win a match at the US Open since Anna Kournikova in 1996.
The American under-18 champion was making her WTA Tour debut and had never before met a player the top 100.
Qualifier Coric, 17, celebrated his first Grand Slam match with a convincing 6-4, 6-1, 6-2 win over 29th-seeded Czech Lukas Rosol, the man who beat Rafael Nadal at Wimbledon two years ago.
"It's an amazing feeling," said Coric.