Well I'm VERY happy to get my prediction right about Del Potro sneaking a set from a tie-break

Currently one set all...with Del Potro a break of serve up!!! Are we set for another huge shock here?!

DEL POTRO DID IT!!!

I can't believe it!!! He ends Federer's six-year unbeaten record in the US Open competition...what a win!

Wow. Didn't see that one coming. I must say, I think Del Potro is going to become a very formidable player in time. Seriously good performance.

Well Kim Clijsters' amazing dream comeback has inspired one Justine Henin...she too will be returning from retirement, next year!

Injury costs you ATP points...just like it did with Nadal in the summer...

...Murray has now slipped to fourth in the world rankings following Novak Djokovic's win in Beijing!

Well let's review the tennis world, seeing as we're almost a week into the Australian Open...

Andy Murray's decision to not defend his titles earlier in the month saw him slip to fifth in the ATP rankings; the first time in almost two years he's not been inside the top 4; with US Open champion Juan Martin del Potro overtaking him.

So he was seeded fifth for the Australian Open, which meant at worst, he'd have to face three of the four players ranked above him...and indeed the draw did just that to him!

He's done brilliantly to reach the second week, and the fourth round (last 16), and yet to drop a set...but should he reach the quarter-finals, that's when things will become excruciatingly difficult for him. Should Rafael Nadal overcome Croatian giant Ivo Karlovic in his fourth round match, he will be Murray's quarter-final opponent. While any of Andy Roddick (who beat Murray at Wimbledon), Fernando Gonzalez (who Murray's struggled against in the past), Marin Cilic (who stunned him in the US Open), or del Potro himself will await him in the semi-final should he succeed against the number 2 seed. Then of course Roger Federer will surely be in the Final waiting for him, Nikolay Davydenko and Djokovic the only other serious contenders in the top half of the draw. Good luck, Andy!!!

As for the women's, both Williams sisters are in the last 16, both yet to drop a set. US Open champion Kim Clijsters was stunned by Nadia Petrova yesterday morning, while Justine Henin continues her good comeback and faces an unseeded player in her fourth round clash, giving her a sound chance of reaching at least the last 8! Good luck to her! And Dinara Safina, well known for not being good enough to be world number 1 for not having a Grand Slam title to her name yet, faces an arguably easy path to at least the semi-finals...her's to lose then!

Here's the full fourth round draw:

Men's:

Roger Federer (1) v Lleyton Hewitt (22)
Fernando Verdasco (9) v Nikolay Davydenko (6)
Novak Djokovic (3) v Lukasz Kubot
Jo-Wilfried Tsonga (10) v Nicolas Almagro (26)
Andy Roddick (7) v Fernando Gonzalez (11)
Marin Cilic (14) v Juan Martin del Potro (4)
Andy Murray (5) v John Isner (33)
Ivo Karlovic v Rafael Nadal (2)

Women's:

Serena Williams (1) v Samantha Stosur (13)
Vera Zvonareva (9) v Victoria Azarenka (7)
Caroline Wozniacki (4) v Na Li (16)
Francesca Schiavone (17) v Venus Williams (6)
Justine Henin v Yanina Wickmayer
Nadia Petrova (19) v Svetland Kuznetsova (3)
Alona Bondarenko (31) v Jie Zheng
Maria Kirilenko v Dinara Safina (2)

Both top seeds prevail in Melbourne...Serena Williams finally ending Justine Henin's dream return, while despite a very hard-fought tiebreak, Murray again went down in straight sets to the king...

Pleased with that result - I really don't like Andy Murray

We know.....



It was a good game but Fed didnt even break sweat... that man is incredible.

Never seen Andy emotional before...was painful to watch at the end but despite everything the others are saying, I don't know if he'll ever win a Grand Slam...his nerves do seem to dangle in the bigger matches

When he faces someone other than Roger in a final I think he'll have a much better chance and he can beat anyone on his day.

Agreed - he'd have easily fared well against Tsonga for example...

New ATP rankings announced...largely due to Nadal winning the Australian Open last year and only making the quarter-finals this year, he's lost BIG points and for the first time in years has slipped out the top 3...Djokovic climbs to an all-time high of number 2, while Murray reclaims number 3...Federer remains top, with Del Potro back down to 5th...

1. Roger Federer (SUI) - 11,350 pts
2. Novak Djokovic (SRB) - 8,310 pts
3. Andy Murray (GBR) - 7,800 pts
4. Rafael Nadal (ESP) - 7,670 pts
5. Juan Martin Del Potro (ARG) - 6,400 pts
6. Nikolay Davydenko (RUS) - 5,290 pts
7. Andy Roddick (USA) - 4,150 pts
8. Robin Soderling (SWE) - 3,375 pts
9. Jo-Wilfried Tsonga (FRA) - 3,235 pts
10. Marin Cilic (CRO) - 2,970 pts

Anyone been keeping up with Wimbledon at all? Of course, with the World Cup here, it becomes slightly less important, but the incredible match between Isner and the french guy is keeping me mezmerised. 5th set, and it's currently 55-55. Absolutely extraordinary.

59-59 it finished last night, due to bad light. Incredible! There's never going to be anything like it.

The thing is, it will either continue in the same fashion or be over in about 10mins

Isner won 70-68 holy hell!!

Poor Isner, completely fatigued, he was swept aside in straight sets today! He's definitely the best player so far in the tournament though!

Well, I do have to comment on this match as I managed to get a seat on Court 18 for the finale yesterday (picture in The Times! ), and there was a fantastic atmosphere and tension - I've never seen so many photographers and press people on the court and on the balcony, and it was genuinely quite emotional to see the delight on Isner's face when he FINALLY pulled off the victory! 11 hours and 5 minutes in the end, and they even managed to play an 11-9 set yesterday!

Absolutely gutting for Mahut of course - I was actually sitting next to someone who had been following him in the qualifiers and obviously she was a bit disappointed, but still clearly appreciative of a EXTRA-extraordinary match! Of course, everyone stood at the end for a rapturous standing ovation lasting about 5 minutes!

Anyway, it was a great to be there while tennis history was being made, and we even got to see the likes of Tim Henman, Ann Jones and Johns Inverdale and McEnroe when they were presented with their awards, and the interviews were good value!

Great day all round - Nadal had a dramatic 5-setter also, but that match has surely redefined everything we ever thought we could expect from a game of tennis, just a wonderful feat of physical and mental fitness!

And it will never be repeated again!

Semi-finals day!

Murray v Nadal is going to be a belter - in the Australian Open in January, Murray played out of his skin to almost beat Nadal in straight sets before he was forced to retire, but this time Nadal will want to beat him!

Novak Djokovic faces Federer's conqueror, Tomas Berdych in the other semi-final; Berdych deserves to reach the Final for his heroics so far, but I can't see Djokovic losing