Tournament favourite Serena Williams overcame an ankle injury to cruise through to the second round of the Australian Open, while world number one Victoria Azarenka and eighth seed Petra Kvitova were also victorious.
But there was no such joy for seventh seed Sara Errani and 12th seed Nadia Petrova, who lost to 42-year-old Kimiko Date-Krumm in a record-breaking result.
Five-time champion Williams was untroubled by Edina Gallovits-Hall as she posted a 6-0 6-0 victory in just 54 minutes, but sent a scare through her camp when she fell awkwardly in the first set.
The third seed was leading 4-0 when she chased down a forehand and collapsed after rolling her ankle. She spent several minutes on the ground before limping to her chair where she received treatment from a trainer.
The delay did little to slow the 31-year-old down though as Williams blitzed through the remainder of the match, dropping just seven points after the injury.
Azarenka looked on track for a similar result but was made to work before eventually defeating Romanian Monica Niculescu 6-1 6-4.
The defending champion raced through the first set, but the world number 49 responded to take the first three games of the second set.
Azarenka recovered to level at 3-3 before breaking in the ninth game and then closing out the match.
Kvitova joined the big guns in the second round with a hard-fought three-set victory over Francesca Schiavone 6-4 2-6 6-2.
Italian Errani, who reach the quarter-finals last year, became the biggest casualty of the tournament when she fell to world number 33 Carla Suarez Navarro 6-4 6-4 in just under 90 minutes.
Date-Krumm, who remarkably last won a match at Melbourne Park in 1996 before retiring for 12 years, became the oldest woman to win a match at the Australian Open with an incredible 6-2 6-0 demolition of Petrova.
The Japanese woman crushed 17 winners in the match and was fully deserving of her place in the second round despite getting a helping hand from Petrova, who committed a staggering 38 unforced errors.
Since coming out of retirement in 2008, it is just the second time the former world number four has reached the second round of a grand slam tournament.
Tenth seed Caroline Wozniacki looked like becoming another casualty when she dropped the first set to German Sabine Lisicki, but the Dane rallied to secure a hard-fought 2-6 6-3 6-3 victory.
World number 36 Lisicki looked on course for the win when she led 3-0 in the final set, but the former world number one responded emphatically to win the last six games and secure her passage into the next round.
Other seeds to get through included Russian Maria Kirilenko (14th seed), Italian Roberta Vinci (16th), Americans Varvara Lepchenko (21st) and Sloane Stephens (29th), Chinese Taipei's Hsieh Su-Wei (26th) and Belgian Yanina Wickmayer (20th).
Polish 31st seed Urszula Radwanska was eliminated, beaten 6-2 6-4 by American Jamie Hampton, and Russian 24th seed Anastasia Pavlyuchenkova was a 7-5 3-6 7-5 loser to Ukrainian Lesia Tsurenko.
Czech 17th seed Lucie Safarova was too good for Croatian Mirjana Lucic-Baroni in a 7-6 (7-4) 6-4 win.
Non-seeded players to progress included Serbian Bojana Jovanovski, Brit Laura Robson, Russian Svetlana Kuznetsova, China's Peng Shuai and France's Kristina Mladenovic.
German Annika Beck, Russians Elena Vesnina and Daria Gavrilova, Croatian Donna Vekic, Israeli Shahar Peer, Kazakh Yulia Putintseva, Japan's Ayumi Morita, Thai Luksika Kumkhum and Slovak Jana Cepelova were all winners.
Uzbek Akgul Amanmuradova and Greece's Eleni Daniilidou progressed, while Spaniard Garbine Muguruza also advanced after a marathon 4-6 6-1 14-12 victory against Slovakian Magdalena Rybarikova.