19:05 CET - Jessica Pegula has got her WTA Finals campaign off to a fine start, defeating defending champion and good friend Coco Gauff in two hours and a quarter, 6-3, 6-7(4), 6-2.
It was a tough serving day yet again for Gauff, who hit a whopping 17 double faults.
18:33 CET - The main draw in Athens has got underway this evening, where sixth seed Nuno Borges has seen off wildcard Stefanos Sakellaridis 7-6(4), 6-3.
17:06 CET - Jannik Sinner is the Paris Masters champion! The Italian was pushed by Felix Auger-Aliassime - who has played well all week - but ultimately, he had just too much quality for the Canadian, winning a really entertaining encounter 6-4, 7-6(4).
It is Sinner's first Masters crown of the year and fifth overall, as well as a fifth title of 2025. He also moves up to number one in the world rankings as a result, replacing rival Carlos Alcaraz.
16:27 CET - World number one Aryna Sabalenka is off and running at the WTA Finals, securing a comfortable 6-3, 6-1 victory over Jasmine Paolini to get her first points on the board. A great start to her campaign.
15:59 CET - Advantage Jannik Sinner in the Paris final. A break in the first game of the match was all the Italian needed, as he claimed the first set 6-4 against Felix Auger-Aliassime.
Both players played some really great stuff, but Sinner - as he always is - was a bit too strong. Can Auger-Aliassime find a way back into the match?
15:45 CET - Janice Tjen has won her first-ever WTA title, with the fourth seed clinching a 6-4, 6-3 victory over Australian third seed Kimberly Birrell in the Chennai final! A massive moment for the Indonesian, who is set to move up to 54th in the world rankings.
13:50 CET - It's almost time for the ATP Paris Masters final between Italy's Jannik Sinner and Felix Auger-Aliassime of Canada.
The seemingly unstoppable Sinner is on another relentless run in the French capital and has beaten his opponent the last two times they've met.
However, Auger-Aliassime did down the redhead twice back in 2022... Can he rediscover that form today? We'll soon find out!
You can follow every point of the match live here from 15:00 CET.
12:00 CET - It's been one incredible year for Victoria Mboko. The Canadian teenager started the season as world number 284 and will end it just outside the top 20, thanks in part to her victory in Hong Kong this week.
Mboko, the third seed this week, has taken down Spain's Cristina Bucsa in three sets, 7-5, 6-7(9), 6-2, to lift her second WTA title, going with the one she won in Montreal earlier this year.
10:22 CET - Well, the fairytale is over for teen Lilli Tagger in Jiujiang. The 17-year-old has been beaten by Anna Blinkova 6-3, 6-3, who claims the title in the Chinese city.
It was an incredible run to the final from the young Austrian, who was making her first main-draw appearance on the WTA Tour.
As for Blinkova, it's just the second title of her career, and first since 2022, so plenty to celebrate for the Russian!
06:30 CET - Hello and welcome to our coverage of the tennis on this blockbuster Sunday! We have finals to look forward to from WTA events in Hong Kong, Jiujiang, Chennai, plus the ATP Paris Masters!
Later on, the WTA Finals continue as the best women in the world hit the hard courts of Riyadh.
First up, though, at 08:30 CET, it's the Jiujiang final between Anna Blinkova and 17-year-old starlet Lilli Tagger, who is not only in her first title match but her first main-draw appearance!
Then at 09:00 CET, we move over to Hong Kong, where another teen, Victoria Mboko, will take on Cristina Bucsa for that title.
The Chennia final will take place from 13:30 CET between Kiberly Birrell and Janice Tjen.
At 15:00 CET, we move to the French capital for an arena showdown between world number two Jannik Sinner and Felix Auger-Aliassime.
At that same time, the action will get started in Saudi Arabia with world number one Aryna Sabalenka taking on Jasmine Paolini, before Coco Gauff plays Jessica Pegula.
The main draws also get underway at the ATP tournaments in Athens and Metz late this afternoon.