There was plenty to look forward to on day four of the Aegon Classic at Edgbaston Priory Club in Birmingham today.

With six last 16 matches scheduled and a round of 32 match to be completed, the only thing that could ruin the day's prospect would be some more of the spoil-sport rain that came yesterday.

Katerina Siniakova and Christina Mchale kicked off proceedings this morning on court number one, producing a match with two very contrasting sets but the same result as Siniakova won 6-4 6-0.

The Czech was did not really play her best tennis, winning just 59 per cent of points on her first serve, but her American opponent was poor, winning only 26 per cent of her second serve points, and she took advantage brilliantly.

Meanwhile, Carla Suarez Navarro was first on centre court, taking on 13th seed Svetlana Kuznetsova in one of just two last 16 ties that pitted two seeded players against each other. Despite being another playing at a level far from her best, Suarez Navarro came through comfortably in two sets, winning 6-3 6-4 in an hour and 20 minutes.

Winning just 66 per cent of points on her first serve and only taking three of her seven break points, she rarely got out of second gear, but remained too good for her Russian opponent. There is more to come from the Spaniard who is a dark horse in the running for this tournament.

Following Suarez Navarro on centre court was the tournament's number one seed, Simona Halep, who faced Klara Koukalova of the Czech Republic, ranked 92 in the world.

The world number three was ruthless from the off, breaking at her first chance to take a 2-0 lead in the first set. Yet, as she attempted to make this 3-0, errors gave her opponent three break points. Koukalova took the second of these to break back immediately and get the match back on serve.

However, another break from Halep made it 3-1, and this quickly became 4-1, 5-1 and 6-1 as she convincingly took the first set after an early lapse in concentration.

Halep continued to demonstrate this conviction from the start of set number two, breaking in the first game to take what would become a 2-0 advantage. 

Koukalova did her best to trouble her Romanian opponent, keeping her on her toes, but it was a routine win for Halep in the end, with her taking the second set 6-3 as she broke again with her first set point.

With 79 per cent of points won on her first serve, 14 winners hit and just 12 errors made, in comparison to Koukalova's 22, the comfortable and convincing win takes Birmingham's top seed through to the quarter finals, where she will face Kristina Mladenovic, who pulled off the shock of the day as she defeated sixth seed Barbaro Strycova.

Having dispatched Eugenie Bouchard in the previous round, winning 6-3 7-6 as the Canadian continues her downward spiral, Mladenovic was full of confidence as she came into another tricky tie against Strycova, a player having a wonderful 2015 after achieving her career-best ranking of 20 in March and equaling her best ever Australian Open run in February.

However, Mladenovic was marvellous today, winning 81 per cent of her first serve points and showing great composure throughout, saving six of the seven break points Strycova saw to keep herself in the match, especially in a tight first set that was eventually won by the unseeded French woman on the tiebreak.

Carrying momentum from her first set, Mladenovic then quickly dispatched her opponent 6-2 in the second and final set, the 22-year-old showcasing her raw talent and using it to progress to the last eight, where another tough match sets itself up as she prepares herself for the world number three, Halep.

Elsewhere, Jelena Jankovic crashed out as fourth seed Angelique Kerber comfortably defeated her in the other match in this round that saw two seeded players clash. Saving all of four break points and winning 75 per cent of points on her first serve, the German cruised into the last eight where she will face Siniakova following her earlier victory.

Suarez Navarro's quarter final opponent was decided a little later in the day due to the rain yesterday that meant Karolina Pliskova's round of 32 match against Johanna Konta had to be stopped and resumed earlier today instead.

Konta was the final remaining hope for the home crowd wanting to see one of their own go all the way this week, but came into the match today a break down, the 6-3 3-6 4-3 scoreline favouring Pliskova, who was on serve. The Czech saw off her spirited opponent to reach the next round, and would be on court later in the afternoon for that tie, playing Zarina Diyas for a place in the quarter-finals.

She came through this far more comfortably, showing very few signs of fatigue despite playing both last night and earlier in the day, and would go on to win the match 6-2 6-2. 

Despite getting just 55 per cent of her first serves in, she won 75 per cent of points on her first serve and was able to save four out of five break points that Diyas saw in the match. Still, she will need to improve on the former statistic if she is to put up a real fight against a confident opponent in Suarez Navarro.

The final quarter-final to be decided saw Sabine Lisicki face Magdalena Rybarikova and Daniela Hantuchova play Portuguese qualifier Michelle Larcher De Brito, with the two winners set to play each other in the next round.

Lisicki came through the first match, winning 7-6 6-4, and Hantuchova through the second, with a 6-4 7-5 scoreline, to conclude the last eight line up.

All four matches will take place tomorrow, with the semi-finals scheduled for Saturday and the final to be played on Sunday.

As for Birmingham's hopes of seeing a British champion this week, they do still have a chance in the doubles, with Briton Heather Watson teaming up with Halep and having reached the quarter-finals. They face Yung-Jan Chan and Jie Zheng for the opportunity to reach the semi-finals, where they will face Suarez Navarro, Halep's potential semi-final opponent in the singles, and her partner Garbine Muguruza.