Hello and welcome to LIVE coverage of day four from the Australian Open. First up on Rod Laver Arena is world No. 3 Maria Sharapova who takes on Karin Knapp.

GAME, SET & MATCH - SHARAPOVA 6-3 4-6 10-8 KNAPP - Finally, we have a winner!! Sharapova serves up three double faults and faces a break point, but produces a spectacular inside out winner to take it to deuce. Two consecutive pinpoint serves prove too good for Knapp as Sharapova comes through the marathon match in soaring temperatures.

BREAK - SHARAPOVA 6-3 4-6 9-8 KNAPP - Sharapova finally makes the breakthrough, and Knapp looks visibly dejected. The Russian races into a 0-30 lead and doesn't allow for the Italian to recover. The third seed has already served for the match and blew three match points. Will she fare any better this time?

SHARAPOVA 6-3 4-6 8-8 KNAPP - In what is almost a carbon copy of the previous game, Knapp can sense the opportunity to break and, therefore, go on to win the match, but Sharapova grinds out the hold.

SHARAPOVA 6-3 4-6 7-8 KNAPP - Sharapova is handed an opportunity to break at 0-30, but a huge forehand from Knapp sparks a stirring fightback and the Italian goes on to hold. Something has got to give soon enough, especially in this heat.

SHARAPOVA 6-3 4-6 7-7 KNAPP - We go on. The Russian holds with ease and prolongs this match in quite unbelievable temperatures. Neither player is giving away much on their serve.

SHARAPOVA 6-3 4-6 6-7 KNAPP - Knapp holds from the sunny end once more. The Italian is digging really deep and has Sharapova looking suitably anxious.

SHARAPOVA 6-3 4-6 6-6 KNAPP - Sharapova cruises to 40-0, but then double faults. Knapp senses an opportunity, but a terrific second serve to the ad-court seals the hold. No tie-break, but each player will be given an extra challenge.

The extreme heat policy has been implemented and each match underway will be stopped at the end of the current set. On courts that have it available, roofs will be closed in order for the matches to continue.

SHARAPOVA 6-3 4-6 5-6 KNAPP - You've got to take your hat off to Knapp, who battles through another service game to hold. Sharapova, who had three match points in her last service game, will no have to serve to stay in the match.

BREAK- SHARAPOVA 6-3 4-6 5-5 KNAPP - My, oh, my! Sharapova has three match points but can't quite get over the line. You know what's coming, and it does, but in the most fortuitous way. Knapp gets a net cord that drops onto Sharapova's side to seal the break.

SHARAPOVA 6-3 4-6 5-4 KNAPP - Sharapova is furious with herself, and rightly so. Knapp fails to land a single first serve in the game, but the Russian lofts each and every return out of the court, gifting her opponent a vital hold from the sunny end. Sharapova will have to serve for the match.

SHARAPOVA 6-3 4-6 5-3 KNAPP - All the pressure is now on Knapp. Sharapova serves out her game with confidence and vigour, and will put pressure on Knapp who is serving from the northern end of the court.

BREAK - SHARAPOVA 6-3 4-6 4-3 KNAPP - Again Sharapova breaks, and again she's in front. She seems to come up with the better tennis at the crucial stages, and gets a vital break - though it takes her five attempts in the game. The Russian will hope not to gift her opponent anything on her serve now...

BREAK - SHARAPOVA 6-3 4-6 3-3 KNAPP - Eurgh! Would you believe it, but Sharapova serves her way into trouble? A couple of wayward strokes has Knapp up at 15-30. The Russian double faults at a vital point to ift her opponent a break point, of which she takes at the first time of asking. It's back on serve in this decider.

SHARAPOVA 6-3 4-6 3-2 KNAPP - Knapp, who has struggled throughout the entirety of the match when serving into the sun, does so again, but manages to squeeze through her service game to close the gap on Sharapova.

SHARAPOVA 6-3 4-6 3-1 KNAPP - The simplest of holds from Sharapova. The third seed races through her game without conceding a point. That previous break of serve whilst Knapp was at the northern end of the court is looking like the decisice point.