The third and last match of the first day action at the WTA Championships in Istanbul was a rematch of the 2012 French Open final between Maria Sharapova and Sara Errani and again Sharapova was victorious, with similar scoreline, 6-3 6-2.

After a slow start of the White Group match and the first four games lasting almost half an hour, Sharapova broke Errani to 4-2 and took control of the encounter, finishing it with 39 winners to Errani's 6, but also 26 unforced errors to Errani's 13.

Errani's season has been stunning with four singles titles, eight doubles titles (including Roland Garros and US Open), the singles final at Roland Garros and now her first ever participation at the WTA Championships. Not to mention that she's also competing in doubles, the only player in Istanbul to play in both fields. However, the Italian is yet to beat a Top 5 player in singles and after today's loss she's 0-22.

To sum up Day 1 in Istanbul, our winners are: Agnieszka Radwanska over Petra Kvitova, Serena Williams over Angelique Kerber and Maria Sharapova over Sara Errani. Tomorrow, Sharapova is also playing the third match of the schedule, against Agnieszka Radwanska. (photo: © Neal Trousdale)

Angelique Kerber came to her first match at the WTA Championships and her first match as a Top 5 player as the only player at the tournament who has defeated Serena Williams this year and the sole loss in Serena's 27 previous matches was at the hands of Kerber. But in today's Red Group match, Serena earned a good old revenge, winning nine of 11 games from 3-all in the first set for a 6-4 6-1 victory. Serena's threatening first serve was at weak 44% and she hit just three aces, but at the net she won 17 of 20 points.

Serena's 2012 results have been mind-blowing. She's won 44 of her last 46 matches and her last 15 against Top 5 players. Not to mention her this year's titles: Charleston, Madrid, Wimbledon, Stanford, Olympics and US Open – all Premier-level or higher. She's practically unstoppable and the fact that she hadn't played since the US Open does not put her even slightly on the unprepared side.

Serena opens tomorrow's action in Istanbul, against Li Na. Kerber has a day off. (photo: © Neal Trousdale)

In the first match of the WTA Championships, in the White Group, Agnieszka Radwanska made her first career victory over Petra Kvitova at the very tournament where the Czech is defending her title. The Pole took advantage of Kvitova's numerous unforced errors and nervousness to record a routine 6-3 6-2 win.

First seven points of the match were Radwanska's (1-0 40-0) and even though Kvitova fought for a long time to hold her serve, eventually she was broken. In the next service game of Kvitova, Radwanska again earned triple break point, leading 3-0 40-0, but this time Kvitova came back and leveled the set. However, Radwanska regained control of the match and nothing could save Kvitova from her -18 differential of winners to unforced errors, compared to Radwanska's +6.

Kvitova has now spoiled two perfect records, 5-0 at the WTA Championships and 3-0 against Radwanska. Of course, nothing is lost yet when it comes to the WTA Championships, the round robin format gives you more than once chance. Kvitova has a day off tomorrow, while Radwanska will play the third match of the day against Maria Sharapova. (photo: © Neal Trousdale)

On Sunday night, the official draw ceremony took place at the $4.9-million WTA Championships in Istanbul, dividing the eight players into two round-robin groups. Serena Williams is the only multiple champion at the year-end finale and is 35-5 against the rest of the field combined (9-1 this season), while Sara Errani is 4-23 and is the only one with a negative head-to-head record against all the three players in her group. Let's have a closer look at the draw.

RED GROUP: (1) Victoria Azarenka, (3) Serena Williams, (5) Angelique Kerber, (8) Li Na

World No.1 Victoria Azarenka is a leader in match wins this season with 67, she's also a title leader with six (tied with Serena Williams), and this fall she's been 13-0 in matches and 26-0 in sets. Serena is fifth in the list of match wins this season with 53, even though inactive this fall, and has a stunning 10-1 head-to-head record against Azarenka. Moreover, two Grand Slams and the Olympics are among Serena's six 2012 titles and three of the six she won without losing a set.  Read more »

The International-level title in Luxembourg may not be a milestone in Venus Williams' career who had won 43 titles before the tournament, including seven Grand Slams, but in the circumstances of her injuries the past two years, the Sjogren's syndrome diagnosis and the title drought dating back to February 2010, the former world No.1 can be delighted with a comeback to the winner's circle.

To win her 44th career title, Venus beat Belinda Bencic in the first round, ninth seed Mona Barthel in the second, in the quarterfinals took out top seed Roberta Vinci, the only seed left at the tournament at that stage, fought for more than two and a half hours against Andrea Petkovic in the semis and finally beat Monica Niculescu, whose only two WTA finals came in Luxembourg and last year she was defeated by Victoria Azarenka in the title match.

Venus beat Niculescu 6-2 6-3, but the scoreline suggests an easier match than it really was. Venus had to stay focused and return the persistent shots of Niculescu for one hour and 23 minutes. (photo: © Neal Trousdale)