Jelena Jankovic and Svetlana Kuznetsova both endured some tense moments before progressing to the third round of the US Open but former champion Lindsay Davenport progressed without being troubled.
Second seed Jankovic was pushed before recording a 6-3 6-7 (5-7) 7-5 triumph over Sofia Arvidsson, while former world No.1 and 1998 champion Davenport posted a 7-5 6-3 second-round triumph over Russian Alisa Kleybanova.
Third seed Kuznetsova got off to a shaky start before registering a 7-6 (7-3) 6-1 victory over Sorana Cirstea, while eighth seed Vera Zvonareva became the highest-seeded player to be sent packing at the year's final major after falling 6-3 6-3 to Tatiana Perebiynis.
Jankovic, who recently lost the world's top ranking after holding it for just a week, looked like she would cruise into the third round, but the 23-year-old Serb squandered a 3-0 lead in the second set before letting slip a similar lead in the tie-breaker.
But in a tense third set which featured some brilliant tennis, Jankovic finally put away the match when world No.63 Arvidsson sent a backhand long for her 54th unforced error to bring to an end the two hour 45 minute contest.
"It was really tough. I am completely out of breath," said Jankovic. "I was pushed to the limit. The last time I played her, she was up 5-1 in the third and I had to come back."
A quarter-finalist at last year's US Open, Jankovic next faces Wimbledon semi-finalist Zheng Jie of China.
Pushed to three sets in the first round, Kuznetsova looked like she might be in for another long day after falling down 4-2 in the first set against world No.53 Cirstea.
However, Kuznetsova started to resemble the player who won the title in 2004 and reached the final last year.
The Russian, who had 17 winners in the first set, raced to a 6-1 lead in the tie-breaker before quickly squeezing the life out of Cirstea in the second set, winning the first five games before eventually wrapping up the match in 73 minutes.
"When I was in a danger situation, I was 4-2 down 40-love on her serve, I just realised I had to go more to the forehand, because on the backhand she was making good shots," Kuznetsova said. "It kind of made me go outside of the court and just defend."
"And in second set, I just started to be so much more confident in my game, just making my moves."
Awaiting Kuznetsova, who finished with 24 winners and just 13 unforced errors, in the third round is 28th seed Katarina Srebotnik.
Zvonareva was her own worst enemy, committing 30 unforced errors in an embarrassing performance against the world's 71st-ranked player who made it to the third round at major for the first time since Wimbledon in 2004.
Swiss 15th seed Patty Schnyder also advanced with a 6-3 6-3 win over Anastasia Pavlyuchenkova, while newly crowned Olympic champion Elena Dementieva coasted into the third round with a 6-2 6-1 destruction of Pauline Parmentier in under an hour.
The Russian fifth seed will next face British No.1 Anne Keothavong, a 6-2 3-6 6-4 winner over 25th seed Francesca Schiavone.