Serena Williams was troubled by windy conditions and some early rust before beating 69th-ranked Pauline Parmentier 6-3, 6-4 to launch her comeback from a four-month lay-off at the Auckland Classic on Tuesday.
In her first outing since she was shocked by Karolina Pliskova in the US Open semi-finals in September, the world number two made a sluggish start to a season in which she is seeking a record 23rd Grand Slam title.
In her first-round match, delayed from Monday night when rain washed out play, Williams struggled initially as France's Parmentier broke the American's first service game and then held to love.
The 35-year-old Williams, using Auckland to warm up for the Australian Open, only had a 48 percent success rate with her first serve and double-faulted four times as she had trouble adjusting to the swirling wind.
But Williams - who shares the Open-era record of 22 Grand Slams with Steffi Graf, and is two behind Margaret Court's all-time record of 24 - grew steadily stronger and finished with her eighth ace.
She said her rhythm returned as the match progressed.
"I'm feeling like I'm trying to get there. Obviously every match counts," she said.
"This wind was getting to me. Every day I've practised here there was no wind and of course today I played and it's so windy. It wasn't fun, it was interesting."
After Williams dropped her opening service game, she fought back from 3-1 down to win five successive games to take the opening set.
Both players suffered service breaks at the start of the second set before Williams broke again to go 4-3 up. She then came from three break points down to claim the crucial eighth game and went on to take the match in 75 minutes.