Shenzhen - Ashleigh Barty has vowed to maintain focus at the season-ending WTA Finals after securing the year-end No.1 ranking on Sunday.
The French Open champion's 5-7, 6-1, 6-2 victory over Belinda Bencic saw her become Australia's first year-end No.1 since Lleyton Hewitt in 2002.
Barty, who started the year ranked 15, has had a meteoric rise and won a tour-topping 53 matches this season.
"It's been an incredible year," Barty told reporters. "I think it's a bit of a bonus to be able to finish year-end world No. 1. It certainly wasn't something that was in my realm at the start of the year."
The 23-year-old said her eye was still on the main prize at the $14 million round-robin tournament.
"I think first and foremost, we'd love to finish off the week here really strongly, then we can worry about celebrating that little thing (No.1 ranking)," Barty said.
"I think it's a bonus now knowing I've started well. But it doesn't change my preparation for Tuesday's match in any regard," she added.
Barty's next match will be a Red Group blockbuster against world No.3 Naomi Osaka, who defeated Petra Kvitova 7-6 (7/1), 4-6, 6-4 in a marathon encounter to thrillingly open the WTA Finals.
It is a chance for Barty to exact revenge on the Japanese sensation who won a three-set final in Beijing earlier this month.
In-form Osaka has won 11 straight matches after titles in Beijing and Osaka.
"It's refreshing knowing that I get to play her now having just played her a few weeks ago in Beijing," Barty said.
"I learnt a lot from the match in Beijing. I'll try to take as much as I can into the match come Tuesday."
Barty's season is set to extend past the WTA Finals as she spearheads Australia's Fed Cup title hopes against France in next month's final.