Both Serena and Venus Williams had a much easier time than Ana Ivanovic at the US Open on Tuesday as the top seed narrowly avoided first-round elimination.
Fourth seed Serena posted a 6-1 6-4 triumph over Ukraine's Kateryna Bondarenko, while seventh seed Venus ousted Australia's Samantha Stosur 6-2 6-3.
Meanwhile, Ivanovic narrowly avoided a stunning upset before emerging with a 6-1 4-6 6-4 victory over Russian Vera Dushevina.
Playing for the first time since pulling out of the Olympic Games with a thumb injury, Ivanovic looked like she would cruise through to the next round after racing to a 5-0 lead and needing just 27 minutes to win the first set against the world's 57th-ranked player.
However, the world number one failed to find her rhythm in the second set when she dropped the final four games and committed 19 of her 40 unforced errors.
Ivanovic, who has never advanced past the fourth round at the US Open, also dropped the first game of the third set with a stunning upset looking possible at the year's final major.
However, Ivanovic broke back, before two unforced errors from the Russian gave Ivanovic the crucial lead break, and she held serve for a 5-3 lead.
The pesky Dushevina fought off a match point to hold serve and Ivanovic then needed to save two break points before finally ending the tense affair when her opponent hit a backhander into the net.
‘When I first went on the court, I was very excited and I started to play really well,’ said Ivanovic, who next will face Julie Coin.
‘Obviously, the lack of practice showed a little bit later.
‘It's going to help me because it was very challenging.
‘I was up 4-2, had a couple of break points and everything was looking fine. I just dropped my concentration for a moment and then it was very hard for me to get back in the game.
‘I just tried to stay strong and to play each point and forget what happened. I'm so happy I managed to do that.
‘So, yeah, definitely, a match like this is going to help me in the next rounds.’
A two-time champion here, Serena enters this tournament in search of her ninth Grand Slam title. However, since her 2002 US Open victory, she has failed to make it past the quarter-finals at Flushing Meadows.
Serena had few problems in improving her record to 41 wins and seven defeats at the US Open as she overwhelmed Bondarenko from the outset, racing to a 4-0 lead and winning the first set in 20 minutes.
The 26-year-old was challenged in the second set but closed things out when she broke Bondarenko's serve for a fourth time.
‘I'm just feeling confident and I feel like I'm just really, really, really enjoying myself,’ Serena said.
‘I loved every moment out there. So it's good.’
Venus had little trouble, dispatching Stosur in one hour 17 minutes as she began her bid for a third US Open title and first in seven years.
The 2000 and 2001 champion, who reached the semi-final last year, improved her record to 48 wins and seven losses, including the 2002 defeat in the final to Serena.
‘I thought it was good,’ Venus said. ‘I thought it was just really straightforward tonight. Nothing super-special. I didn't try anything too crazy.
‘If anything, I tried something a little opposite than I usually try. I think I tried a little less and tried to be a little more consistent, so that was actually something new.’
The Williams sisters are in the same half of the draw here and could meet in the quarter-finals.
Sixth seed Dinara Safina continued her outstanding summer with a 6-3 6-4 thrashing of Kristie Haerim Ahn.
Safina was bit sloppy, winning just over 60% of her first serves and committing 35 unforced errors, but she still had far too much Ahn, who was appearing in her first Grand Slam match.
‘I like to take one match at a time because every opponent is dangerous,’ Safina said.
‘Maybe today I was not 100% focused. I was a little bit achy, and it went straight 6-3 6-4. I was struggling today on the court. It's important I go out there and give my 100% every day.’
There was an early upset when 11th seed Daniela Hantuchova endured a 6-4 6-2 setback to Anna-Lena Groenefeld.
Virginie Razzano, the 31st seed, also exited, losing 6-4 6-1 to Timea Bacsinszky.
Ninth-seeded Agnieszka Radwanska advanced to the second round with a 6-4 6-2 triumph over Yaroslava Shvedova.
Other seeded winners included Amelie Mauresmo, Agnes Szavay, Flavia Pennetta, Alize Cornet, Dominika Cibulkova, Nadia Petrova, Nicole Vaidisova, Alona Bondarenko - the sister of Kateryna - and Ai Sugiyama.
