Ana Ivanovic out into round 1 of the us open 2016. Allertova win's

Ana Ivanovic arrived in New York with her lowest ranking (No. 31) in a half-dozen years. But that didn’t mean the former No. 1 and 2008 Roland Garros titlist didn’t have second-week ambitions in Flushing Meadows, where the 28-year-old Serb has reached the fourth round or better on five occasions, including a career-best run to the quarterfinals in 2012.

But for the second straight year, the No. 29 seed finds herself out of the tournament in the round of 128, having suffered a 7-6, 6-1 loss to 89th-ranked Czech baseliner Denisa Allertova in Louis Armstrong Stadium.

Ivanovic had her chances. She served for the first set at 5-4 and again at 6-5, but her serve let her down time and again. She was hampered by four double faults in the opening set alone, and was simply outclassed in the tiebreak, 7-4.

Broken in the first game of the opening set, Allertova returned the favor in the second, consolidating the break for a quick 2-0 advantage. She would notch two more breaks in the fifth and seventh games to seal the one-hour, 18-minute upset, undoubtedly the biggest win of her young career.

“It’s an amazing feeling right now,” said Allertova, who is making her second main-draw appearance at the US Open. “I’m so happy. It was a tough match. She’s a great player. But I just focused on every point and tried to play my best.”