Maria Sharapova was made to work hard for a place in the second round of the US Open, eventually seeing off American Laura Granville in three tough sets.
The Wimbledon champion has not been in the best of form since her triumph at SW19 and looked in danger deep in the third set.
But she held her nerve to break to love in the 11th game and come through 6-3 5-7 7-5.
Sharapova will play unseeded Jelena Jankovic in the second round.
"My game went off for a while," said the 17-year-old. "I went to La-La Land but I came back to Earth."
Venus Williams, the 11th seed, made it through to the last 64 with a 6-3 7-6 win over Hungary's Petra Mandula and goes on to meet fellow American Shikha Uberoi.
"It's vital not to look too far ahead," said Williams. "I'm only looking at the second round for now."
Top seed Justine Henin-Hardenne had to fight back from a second-set scare before she beat Nicole Vaidisova earlier on Tuesday.
Henin-Hardenne cruised through the first set in just 17 minutes but her Czech opponent rallied in the second.
Vaidisova broke the Belgian twice to claim a 4-1 lead and the match looked destined for a deciding third set.
But the champion pulled herself together and reeled off five games in a row to close out the match 6-1 6-4.
"It was really tough conditions today," said Henin-Hardenne. "I played well in the first set and then I started to sleep a little bit and she started to play better.
"When I was 4-1 down I found my game again. It's not easy playing the first match but I'm happy I won it."
Two of the players expected to challenge Henin-Hardenne for the title breezed into the second round.
Number five seed and 1998 champion Lindsay Davenport, who has won her last four tournaments, defeated Lubomira Kurhajcova of Slovakia 6-4 6-0 in 50 minutes.
"It feels similar to 1998 when I also came in after a great run on the hardcourts," said the 28-year-old.
"It's amazing what a little confidence can do. After the first set I was cruising."
And French Open champion Anastasia Myskina, seeded four, thrashed Ludmila Cervanova of Slovakia 6-1 6-0 in just 42 minutes.
Mary Pierce made an impressive start with a 6-1 6-2 defeat of fellow Frenchwoman Emilie Loit.
The latest Russian hopeful, 17-year-old Maria Kirilenko, had an excellent 7-6 (7-3) 6-3 win over compatriot Elena Likhovtseva, and Americans Lisa Raymond and Jill Craybas also progressed.