The San Diego Open heads into the business end on Thursday with Day Four seeing the Quarter-Finals take place. Before the action begins, the preview looks at all four ties.

It has mainly been a story of the big names needing games and wins doing just that so far this week, with a leading trio in particular coming into this weekend starved on confidence and momentum.

Four quality ties await and four will remain on Day Five, but who prevails?

First up in the Quarter-Finals, it is Sofia Kenin who has so far played twice winning in straight sets over sixth seed, Veronika Kudermetova and then seeing off Katie Volynets in the Last 16. She now tackles Anastasia Potapova.

Potapova since losing first round to Clara Tauson at the US Open will face Kenin after defeating Alycia Parks in three sets and top seed, Ons Jabeur in straight sets. After poor form at times in recent months, it is a good chance for the Russian this week.

Like it is for Caroline Garcia who well documented has not won first rounds in most of her tournaments in recent months. This includes the US Open when she lost to Wang Yafan. But it was a tougher test and a much better display as she defeated Sloane Stephens in her first match of the tournament.

Now Danielle Collins awaits who as she proved in Montreal is still capable of Grand Slam final form on her day and she saw off Jelena Ostapenko in the Last 16 after coming from a set down. She holds a 2-0 Head to Head advantage over Garcia going into their clash.

Then it is likely the tie of the round as Beatriz Haddad Maia who came through two three set gruellers against Leylah Fernandez and Marta Kostyuk respectively faces Barbora Krejcikova.

The former World Number Two breezed past Anhelina Kalinina and like Garcia and Sakkari who plays in the last Quarter-Final, she has struggled for form and getting past even her first tie.

After winning Dubai, she has consistently had problems with a left leg injury at Wimbledon which has derailed her progress and with big tournaments thick and fast, she has not yet hit top form again. She holds a 2-0 Head to Head lead over the Brazilian stretching back to 2016.

Before it is the turn of Maria Sakkari who benefitted from a walk-over albeit ahead against Camila Osorio so technically not a confidence booster. But now plays an easier opponent in a way in Emma Navarro for a spot in the semi-finals. Likely the favourite for the title already given that others have been embroiled in long matches and against bigger names.

Anastasia Potapova v Sofia Kenin (USA)

Danielle Collins (USA) v Caroline Garcia [2] (FRA)

Beatriz Haddad Maia [7] (BRA) v Barbora Krejcikova [4] (CZE)

Maria Sakkari [3] (GRE) v Emma Navarro (USA)