Defending champion Justine Henin-Hardenne was given a scare by 15-year-old Czech Nicole Vaidisova before claiming her place in the U.S. Open second round on Tuesday.
The top-seeded Belgian breezed through the first set but trailed 4-1 in the second before coming back with five straight games to seal a 6-1, 6-4 victory.
Henin-Hardenne will meet Tzipora Obziler of Israel or Angelique Widjaja of Indonesia in the second round.
Against an opponent making her main draw debut at a Grand Slam event, Olympic champion Henin-Hardenne cruised through the first set in just 17 minutes.
But the 15-year-old, who won her first Tour title in Vancouver this month in only her third WTA event, showed courage to break the Belgian twice as Henin-Hardenne struggled in the windy conditions.
Just when it looked like she might be forced into a deciding set, however, the Belgian's experience proved crucial and a series of unforced errors from Vaidisova gave the top seed victory.