Wozniacki to serve in this opening service game.

WINNER! Wozniacki is through! A fantastic match. Sharapova really gave it her best shot, but she was undone by too many unforced errors. That serve also needs to be looked at, but Wozniacki was as solid as a rock. She was equal to everything that was thrown at her by Sharapova. Sharapova threw in 35 unforced errors compared to 10 by Wozniacki, which says it all. She was also let down by nine double faults.

Sharapova saves a match point with a wonderful volley on the stretch after Wozniacki dashes to thump a forehand across court. Fantastic play by Sharapova, who is certainly not finished out there. The Dane will serve for it.

Wozniacki will take great confidence from this performance if she wins. She has been like a rock in the face of some fierce groundstrokes by the Russian. Really has been impressive. Sharapova will serve to stay alive.

BREAK! Sharapova's service problems come back to haunt her. She continues to throw in double faults at the worst possible moments. She drops serve and the match is now firmly in Wozniacki's hands.

Superb defensive play by Wozniacki, who is showing why she is the top seed at this tournament. Sharapova would have blown a lot of women off the court with the venom of her shots, but the Danish player has refused to buckle.

Sharapova continues to grow in confidence out there. Wozniacki seems to be content to stay with Sharapova at the moment. The Russian is showing glimpses of the form that helped her win the US Open in 2006. If she can get that serve in working order, she can put the Dane under more pressure.

This match has been going for one hour and 24 minutes. Sharapova really testing Wozniacki, but so far the Dane has been equal to the task. Sharapova has hit 22 winners to nine by the Dane, but that explains the amount of unforced errors Sharapova has been throwing in. She is up to 24 now in the match.

First ace of the match for Sharapova in that game. She sneaks ahead by the odd game in three. What she would give for a break out there. That would really liven things up.

A rip-snorting second game. Sharapova throwing everything, but the kitchen sink at the Dane, but Wozniacki is not the top seed for nothing. She resists the Russian's advances to hold serve.

Three break points saved and two double faults, but Sharapova somehow gets out of that game with her serve intact. She is under so much scrutiny on her serve.

SET! Not much between this pair, but Wozniacki benefits from making less errors to take the set. Sharapova needs to improve her service game in the second set, but she is hitting the ball well enough. The ball strike of Sharapova is in good nick, but 16 unforced errors flew off her racket there compared to only five by Wozniacki. Sharapova gets us under way for the second set.

BREAK! Sharapova would probably prefer to let Wozniacki serve throughout this match. She surrendered that service game without forcing the Dane to do very much. Wozniacki will serve for it.

BREAK! Sharapova right back in this contest. She breaks back. The only concern about her is whether or not her serve will hold up.

Sharapova looked destined to fall 5-1 behind, but she rallies to stave off several break points. Better play by the 14th seed.

A solid service game by Wozniacki in dropping only one point there. In contrast to the Russian, Wozniacki has got 92% of her first serves in winning 64% of her points on first serve.

BREAK! Sharapova is hit with a touch of the jitters on her serve. She drops serve after throwing in three double faults to hand the initiative to the Russian. Sharapova is moving well and grunting loudly, but she looks fragile on serve.

The top seed from Denmark holds serve. Both women really getting some pace on their groundstrokes out there.

Sharapova returns the favour with a decent effort of her own.

Strong first service game by Wozniacki. Looks in the mood.