The top seed Caroline Wozniacki has raced to a straight sets win in her opening match of the ASB tennis classic in Auckland.
The 27-year-old Dane took less than an hour to beat American Madison Brengle 6-3, 6-love.
Wozniacki, the world number three, will rise to the top of the world rankings if she wins the Auckland tournament.
Wozniacki is still chasing searching for her first grand slam triumph but after emerging victorious in the elite eight-woman event in Singapore, her raised levels of play could see her make that breakthrough at the Australian Open in Melbourne later this month.
Wozniacki is also searching for a first triumph in Auckland after reaching the final in 2015 and despite being tested by Brengle early the contest, the Dane pulled away once she found her rhythm and claimed the last seven games to seal victory.
"I thought I played pretty well, especially considering it's the first match back of the year," Wozniacki told reporters. "It took me a couple of games to kind of just get the rhythm and then I started playing better and better.
"I'm just trying to get my legs moving, trying to make the right decisions, wait for the right shots to play aggressive and go for it, and find the right balance of offence and defence."
The win set up a second round encounter against Croatia's Petra Martic, who overcame Czech player Marketa Vondrousova 7-6(2) 6-3 in their first round tie to advance.
Elsewhere, former world number two and 2013 Auckland champion Agnieszka Radwanska was forced to dig deep to remain on a semi-final collision course with Wozniacki when the Pole eked out a 6-2 4-6 6-2 victory over Brazil's Beatriz Haddad Maia.
"I'm just very happy to win my first match of 2018, and I think it was good timing to come back and do it here in Auckland after five years," Radwanska, who has seen her ranking drop to 28th after a poor 2017, said in her on-court interview.
New Zealander Jade Lewis lost her opening round match to Slovakia's Viktoria Kuzmova, 4-6 3-6.
Third seed Barbora Strycova was also taken the distance in her first round encounter against Italy's Sara Errani, the Czech emerging with a 6-4 6-7(3) 6-4 victory to set up a second round tie against Sweden's Johanna Larsson.
The day did not pass without three upsets, however, with defending champion and fifth seed Lauren Davis losing 6-1 6-2 to fellow American Sachia Vickery, while sixth seed Yulia Putintseva and seventh seed Mona Barthel both suffered straight set losses.