In the first set there were a number of breaks early on with the Czech player eventually taking it, but in the second Li was unstoppable on her way to a 6-0 win.
After a brutal final set, Li claimed the all important break late on to take it 8-6. Read how the action unfolded below.
5.13pmHello all and thanks for joining me for this third round clash between Klara Zakopalova and Li Na. It's seed 32 against seed six in what could be a close match.
5.16pmZakopalova has dropped in the rankings a lot over the past few months so she has quite a lot to prove. She was 20th in April and is now 43rd. It's not a good run of form for her, and she would do very well to come through this in truth.
5.18pmThe warm-ups will be coming to an end soon, so we'll be underway before too long. Li is sixth in the world and always there or thereabouts in Slams.
5.19pmLi to serve first, so let's get straight to the action!
5.21pmA good start from Li here, and she races into a 40-15 lead.
5.23pmHowever, good movement on the baseline and a fine winner sees the Czech level it at deuce.
Zakopalova *1-0 LiBREAK! After battling back to advantage, Zakopalova gets a huge slice of luck as her return hits the net and just goes over. Early break for her, though. Great start.
Zakopalova 1-1* LiBREAK! Li is battling back. A double fault from the Czech moves the Chinese 15-40 up and she takes the break back at the first time of asking. Not good serving from either player so far.
5.28pmZakopalova moves to the net for what must be a winner, but goes wide to hand a reprieve to Li at 15-30.
5.29pmLi goes wide with a forehand and there's another break point up for grabs...
5.29pmA big ace down the middle saves it! First of the match. Deuce.
Zakopalova *1-2 LiAgain the Czech goes wide on break point, but Li doesn't want to capitalise when she has her own advantage and skews a shot into the stands. However, she finally finishes it with an ace.
Zakopalova 2-2* LiFinally a comfortable service hold! The first so far that hasn't been contested to deuce, and Zakopalova levels the set at two apiece.
5.38pmZakopalova has the chance to go 0-30 up but mishits a drop shot and Li takes advantage.
Zakopalova *2-3 LiGood service game from Li, who is looking comfortable with the ball now. It's finely poised this one and the set could still go either way.
5.42pmThat's the second time Li has found the edge of her racquet, with the Czech going up 30-15 in the game because of it. That soon becomes 40-15 and a break doesn't look likely all of a sudden.
Zakopalova 3-3* LiAnd indeed it doesn't happen. Half way through the set and I've no idea who'll claim it.
5.46pmBoth players are making errors, with balls going long almost as often as they are in. Zakopalova with a nice return at the feet of Li and has a break point.
Zakopalova *4-3 LiBREAK! At the second time of asking in the game, Li nets and the Czech player breaks, and has her nose in front again.
Zakopalova 5-3* LiGood play form Zakopalova in the rallies in that game. She forces an error from Li to go 30-15 up and gets game point with a wide return from the Chinese. Then another good rally goes the Czech's way and she's one away from the opening set here.
5.53pmGood response from Li, who starts her next game with an ace down the middle.
Zakopalova *5-4 LiA very comfortable hold from Li, which puts a bit of pressure on Zakopalova's next serve here.
5.56pmShe doesn't appear to be feeling any, though, as she quickly goes 30-0 up after to Li errors.
Zakopalova 6-4 0-0* LiSET! Li smacks a terrible second serve into the tramlines to give the Czech set point, and she then goes long to gift her the set. Li was very poor there and the Czech did enough to take advantage.
Zakopalova 6-4 *0-1 LiMuch more accurate from Li. Not just with her serve but her shots from the baseline were finding the target, which helped her to a strong and important hold early in the set.
6.05pmReally good second serve one-two there for the little Czech for 30-15.
6.08pmBreak point for Li now from 15-40 down following a fine cross-court forehand winner.
Zakopalova 6-4 0-2* LiBREAK! First blood in the second goes to Li. That was a show of nerves from Zakopalova, who netted at exactly the wrong time.
6.10pmStrong stuff form Li, whose shot is right at the feet of her opponent, who can only return into the net.
6.11pmThe Czech battles back to deuce, with Li this time netting.
Zakopalova 6-4 *0-3 LiIt's an important hold for Li, who powers a forehand to force the ball long from Zakopalova. Li means business in this set after the surprise of losing the first.
6.15pmNow the Chinese is up 0-30 on the Czech's serve. This set is looking completely different.
Zakopalova 6-4 0-4* LiBREAK! Really strong fightback from Li, but she owes a lot to a really poor attempt at a drop shot from the Czech. This set is heading towards a bagel.
6.19pmWhat a brilliant backhand down the line from Li! It's a good rally with neither player budging, and it needed a shot of that quality to win the point.
Zakopalova 6-4 *0-5 LiReally strong hold from Li, who is racing to this set. It's been a fine response and Zakopalova looks to have given this one up in order to fight for the third.
6.22pmLi fires in a backhand from around the post and clips the line on the stretch. What a shot!
6.23pmThere seems to be nothing the Czech can do right now as Li has three set points...
6.33pmThis is better from Li. She's up on serve 30-15 after winning a rally when Zakopalova put a forehand long.
Zakopalova 6-4 0-6 *1-2 LiNow she's in front in the match, and that was a quite brilliant backhand winner to claim the game. A really good hold after her disastrous previous attempt.
Zakopalova 6-4 0-6 2-2* LiZakopalova's turn to be solid with the ball, despite Li getting the first point with a fine winner. I really can't predict the way this is going.
6.40pmReally poor serving again from Li. A double fault hands the Czech a 0-30 advantage in this important game... but she responds with a wide serve and a one-two finish.
6.40pmAn excellent forehand winner from the baseline from Zakopalova gives her break point...
Zakopalova 6-4 0-6 *2-3 LiLi saves it - which is the fourth overall she has fended off - and then finally finds a couple of good serves to just about hold. It was close, but she managed it. Over to you, Klara.
Zakopalova 6-4 0-6 3-3* LiComfortable hold from the Czech. Nothing is giving just yet from either player, but it will have to sooner or later. Who has more nerve?
Zakopalova 6-4 0-6 *3-4 LiShe's was starting to look a bit more confident, Li. She looks to be controlling that service game, but a fightback from her opponent gets it back to deuce. Then Zakopalova gains advantage but a great Li forehand forces her into the error and then finally wraps up the hold. Something has to give soon and it looks more likely to come from Li.
Zakopalova 6-4 0-6 4-4* LiWhat's that, an easy service hold? This match just keeps on surprising. Li fights back late in the game with a big forehand down the line, then Zakopalova nets, but when Li goes long we go back to parity. We're at the business end now.
6.57pmReally good play from Li! She has Zakopalova running all over the baseline before hitting the clean winner down the line.
6.58pmBut what a response from Zakopalova! Li goes for the smash, but it's read and returned down the line off the backhand. And now a double fault levels the game, 30-30.
Zakopalova 6-4 0-6 *4-5 LiAn unforced error lets Li off the hook and she's now one away from taking the win. It's been a slog, and she still has to break remember.
7.02pmShe's going for the break to win it, and pulls us back to 30-30 here.
Zakopalova 6-4 0-6 5-5* LiLi nets and Zakopalova holds on. Nothing is giving at the moment, so I can't see where a break is coming from!
7.04pmBoth are hitting well from the baseline, but Li's shot goes an inch wide and the Czech has a look in at 15-30...
7.05pmLi nets a backhand form a big Zakopalova shot and now two big break points!
Zakopalova 6-4 0-6 *6-5 LiBREAK! There it is! At the first time of asking in the game, Zakopalova controls a point from the baseline before stepping into the big forehand and wrong-footing her opponent with the winner. Now she will serve for a place in the fourth round.
7.08pmIt's a poor second serve from the Czech, and Li has a chance here at 15-30.
7.08pmBig, big backhand from the back of the court from Zakopalova - really brave tennis to level it.
7.09pmHowever, Li now has a break point thanks to a double fault of all things...
Zakopalova 6-4 0-6 6-6* LiBREAK! What a forehand winner from Li! The Czech has bottled it, it must be said, but still that's a fine shot to send us back on serve. No tie-break, remember.
Zakopalova 6-4 0-6 *6-7 LiComfortable hold for Li, as Zakopalova hits a forehand into the tramlines. Can she break again for the win here, or will we go on all night?
7.15pmWhat a shot! Zakopalova is desperately hanging on in the point, but can do nothing about the lob right into the corner.
7.16pmBrilliant from Zakopalova, who hangs on before getting on top of the point and hitting the winner for 15-30.
Zakopalova 6-4 0-6 6-8 LiGAME, SET AND MATCH LI! The Chinese gets her match point when Zakopalova goes long. The first is saved by an error from Li, but she finally converts one with the Czech netting! Great match.
7.22pmSo there we have it. Li wins an epic battle. She was brilliant and awful in equal measure and will have to improve to go any further.
7.23pmThanks for joining me for this one, and be sure to stick around on site for reports and reaction from the world of sport. Goodbye!