Hello and welcome to LIVE coverage from world number one Serena Williams' fourth round clash against 24th seed Garbine Muguruza

That was some battle for Serena Williams to have to come through but credit to Muguruza as she once again proved to be a formidable opponent for the American. Nonetheless it is Serena who is through to the last eight where she will face 10th seed and last year's runner-up Dominika Cibulkova.

Williams 2-6 6-3 6-2 Muguruza. Game, set and match. A 194kph out wide for an ace brings up two match points for Williams but the world number one only needs the one as Muguruza goes just wide and long with an inside out forehand.

Williams 2-6 6-3 5-2 Muguruza. Break. The Spaniard goes for a looping backhand across court to give herself a little more time (signs she's getting tired, perhaps) before going for the thumping change-of-direction backhand winner down the line. But she nets that final shot to gift Williams another break point. Serena squanders it with a poor forehand error but Muguruza also saves a second break point with an ace. But back-to-back errors from the 21-year-old, one off either wing, and Williams has the double break cushion that leaves her serving for the match after the change of ends.

Williams 2-6 6-3 4-2 Muguruza. A crushing forehand winner from Muguruza puts more pressure on Williams at 15-15 but the American races through the next three points and sealing the hold with another ace and a scream of "come on". The world number one is potentially just two games away now.

Williams 2-6 6-3 3-2 Muguruza. The Spaniard was in danger of being bulldozed in this final set but she races through a service hold of her own for the loss of just the one point, throwing in an ace of her own before sealing it with a forehand winner

Williams 2-6 6-3 3-1 Muguruza. Aces numbers 14 and 15 from Williams bring up two game points. But she only needs the one to consolidate the break when Muguruza sends a forehand return long across court. Is that the end of the Spanaird's challenge today?

Williams 2-6 6-3 2-1 Muguruza. Break. Muguruza just pulls up on a forehand across court and sends it sailing well long of the baseline to hand Williams another two break points. This time only the one is needed as an attempted backhand down the line from the Spaniard drifts wide. Momentum is swinging Williams' way finally. Muguruza has enjoyed any number of opportunities on the Williams serve though, she might not be done just yet.

Williams 2-6 6-3 1-1 Muguruza. The Spaniard stops mid-point to challenge a call only to be shown by hawkeye that the ball did catch the back of the line. Back-to-back huge returns from Muguruza, though, followed by a double fault from Serena and it's two break points for the Spaniard. The first goes begging on a shockingly poor forehand volley that sails long of the baseline while Williams saves the second by finally finding a first serve. The world number one gets a little lucky on a third when Muguruza slices a forehand long and the Spaniard denies Williams on another game point with an exchange up at the net. Williams hands Muguruza another break point with a double fault but promptly takes it away with an ace and a fifth with a service winner. And eventually Williams does go on to hold with a couple of much bigger first serves. What can Muguruza do now?

Williams 2-6 6-3 0-1 Muguruza. It's all just starting to come together for Williams now as she earns herself another two break points. Muguruza saves the first with a dipping passing shot attempt that Williams can only volley back into the net and then also a secod with a great serve that Williams cannot return in play. A first game point goes begging for the Spaniard on a low netted cross court backhand while a second goes with a forehand just long. Williams squanders a third break point with another poor return and this time Muguruza does go on to hold when Serena dumps another return into the net. Great hold for the Spaniard and an important one at that.

Williams 2-6 6-3 Muguruza. Set. Four massive serves, including a couple of aces, and Williams levels up the match at one set apiece with a second love service hold in quick succession. Muguruza definitely tailed off towards the end of that second set. Can she find her form again in the third ro will this be a romp now for the world number one?

Williams 2-6 5-3 Muguruza. Break. A second double from Muguruza allows Williams to take a 0-30 lead against the Spaniard's serve. Muguruza gets one point back with a body serve but her forehand on the next point catches the top of the tape and sits up giving Serena plenty of time to find the forehand winner down the line. Two break points to the American. She only needs the one, though, Muguruza netting a forehand. Williams will serve to take this into a decisive third set.

Williams 2-6 4-3 Muguruza. A blink-and-you'll-miss-it service hold from Williams is sealed with ace number eight to put all the pressure back on Muguruza, who is constantly playing catch-up in this set.

Williams 2-6 3-3 Muguruza. The Spaniard just makes a forehand drive from up at the net after getting herself caught up. She lands the ball right on the back of the line but that was very close to going out and handing Williams another break point. Instead Muguruza goes on to hold and stay level when Williams hesitates over coming in, decides not to and drops her ball short allowing Muguruza to take control of the point and draw the error from the American.

Williams 2-6 3-2 Muguruza. A much needed love service hold for Williams although three out of the four points are still a real battle as Muguruza hits harder and harder and forces Williams to produce winners.

Williams 2-6 2-2 Muguruza. Williams gets a look at a second serve and looks like she might get on top in the rally but Muguruza levels at 30-all with a step up the court and a forehand winner across court. The Spaniard has a nasty fall on the baseline after getting her feet caught up trying to change direction for the Williams wrong-footing forehand winner. But she recovers quickly to find an ace and save the break point. Williams brings up a second break point with a forehand that catches the top of the tape and dribbles over for a drop shot winner. But again Serena can't take advantage and Muguruza goes on to hold by out-hitting Williams once again, the American going wide with a change-of-direction forehand down the line.

Williams 2-6 2-1 Muguruza. Break. Huge hitting once again from the Spaniard earns her three immediate break back points - a wrong-footing forehand winner, a huge forehand down the line and a inside out forehand winner up at the net off the defensive short ball from Williams. Serena saves the first with an ace but she can do nothing about the second as Muguruza again finds an aggressive forehand return of serve that draws an error (a forehand into the net) from Williams. Back on serve in this second set, albeit with Muguruza still trailing by a game.

Williams 2-6 2-0 Muguruza. Break. The Spaniard just misses a backhand down the line, just very marginally, to hand Williams two break points. Muguruza saves the first with another stunning backhand down the line, wrong-footing Williams yet again. But this time she can do nothing about the second, Murguruza peppering the baseline once again before going for too much on a forehand down the centre of the court and hitting long.

Williams 2-6 1-0 Muguruza. Muguruza out-hits Williams once again, although on one of the points she just misses her cross court forehand into the tramlines. It puts pressure on the American's serve at 40-30 but Williams comes up with a second serve ace right into the corner down the centre of the court.

Williams 2-6 Muguruza. Set. Williams reads the Muguruza serve well but gets a little lucky when her forehand catches the top of the tape and is taken even further away from Muguruza. Three more break back points. The first goes begging with a wrong-footing forehand winner from Muguruza and the second when Williams connects on an inside out forehand late and sends it wide across court. Muguruza saves the third with an ace before bringing up set point when Williams again misses a backhand. And one set point is all it takes, Williams going long with a forehand return of a great serve from the Spaniard. From 2-1 down, Muguruza has reeled off five straight games to snatch the first set once again from Williams. What a performance so far from the 21-year-old!

Williams 2-5 Muguruza. Break. The Spaniard is picking off Serena's serve time and time again as she levels at 15-all with a thumping backhand return winner down the lin. Muguruza earns herself another break point for the double break lead with a deep forehand return and brutal forehand down the line that Williams simply cannot deal with, pulling her defensive backhand well wide across court. Sure enough Muguruza does secure the double break, Williams going wide with a cross court forehand this time, and the Spaniard will serve for the opening set after the change of ends.