Two players who won their opening matches in the White Group go head to head, while Serena Williams looks to bounce back from her thrashing at the hands of Simona Halep as the WTA Finals in Singapore promises another enthralling day of action.
Apart from three singles matches – two in the White Group and one in the Red Group – there will be doubles action as well, with Sania Mirza and her partner Cara Black looking to go through to the next round with a win over Raquel Kops-Jones and Abigail Spears.
Sania is the lone Indian featuring in this season-ending tournament and the Hyderabadi will be keen to go as far as possible with her Zimbabwean opponent.
Starting off proceedings on Day 4 will be Caroline Wozniacki and Agnieszka Radwanska, two ladies who beat Maria Sharapova and Petra Kvitova respectively in their opening matches of the WTA Finals on Tuesday.
Wozniacki showed plenty of fight and quality to topple Sharapova in the first match, in three hard-fought sets.
"I'm feeling a little tired, but it was a great match and great to make a winning start," Wozniacki said after her win over Sharapova. "It's always tough to play your first match and get into rhythm on a new court.
"I'm just so happy to win and the crowd was unbelievable out there.
The Dane has shown plenty of signs of her old form, form which kept her as the world number one for a considerable period of time and the 24-year-old will be keen to take one large step towards the semifinals with a victory over her Polish opponent on Thursday.
"Everyone wants to be here. At the start of the year it's our goal," added Wozniacki. "In the middle of the year it didn't look like I had a chance but I had an amazing summer, reached the US Open and now I'm back. It feels great."
Radwanska is coming off an impressive victory over the big-hitting Kvitova and will be confident of making it two wins out of two.
The second singles match of the day will be between Sharapova and Kvitova, and both players will know they cannot afford another loss.
Sharapova saw her slim hopes of beating Serena Williams to the year-end world number sport take a considerable blow with the loss to Wozniacki, and the tall Russian will be keen to make up for that with a victory over the Wimbledon champions Kvitova, who will also be equally desperate to notch up her first win at the WTA Finals in Singapore.
"I think probably we were both favourites in our matches and of course in our group," Kvitova said after her loss to Radwanska. "That's what happens in tennis. I know that Caro beat her [Sharapova] in US Open, so she knew it would be difficult.
"I thought that I can beat Aga as well, but everybody is really up for this week and the matches can all go both ways."
Rounding off the singles matches of Day 4 will be Serena Williams vs Eugenie Bouchard. Serena suffered the joint biggest loss of her career to Halep on Tuesday, and the American will want to make amends ASAP.
"My forehand was off -- I guess it went on an early vacation," Williams said after her dreadful display against Halep. "Lord knows my serve was as well.
"My serve, I don't even... I don't know. My serve was at best in the 10 and under division in juniors.
"Yeah, it was actually embarrassing I think describes the way I played. Yeah, very embarrassing."
Serena will definitely start as the heavy favourite against Bouchard, who has struggled on her WTA Finals debut. The young Canadian lost to Halep in her first match, before going down in straight sets to Ana Ivanovic on Wednesday.
While Bouchard is not entirely out of contention for a semifinal berth, the 20-year-old will know she needs to win, and win big against Williams if she is to stay in Singapore a little longer.
"For me, you know, I kind of got killed by the two players in my pool not named Serena, so I think it can only get better from here," said Bouchard.
"I'm just looking forward to the match. Never say never, but it's probably my last match of the year, so I'm going to just give it my all. To end with Serena is kind of cool."
Where to Watch Live
Day 4 of the WTA Tour Finals will begin at 1.30 pm Singapore time (11 am IST, 6.30 am BST, 1.30 am ET) with Radwanska and Wozniacki taking court. That match will immediately be followed by Maria Sharapova vs Petra Kvitova.
The night session will start at 7.30 pm local time (5 pm IST) with Serena Williams taking on Eugenie Bouchard. Sania Mirza and Cara Black will play their doubles match soon after.