5-4 - Some meaty serving - including a second serve ace at 40-0 - gives Hewitt the game, but the quarter-finals now beckon for the champion.

4-3 - Hewitt keeps the pressure on with an easy hold to love, but he has to start converting those break points if he wants to turn this around.

3-2 - Hewitt still has some nice shots in his locker, and he holds to 15 thanks to an ace at 40-15. The crowd rise to acclaim his efforts, but it doesn't look like they'll be watching him for much longer.

40-40 - A brilliant, stooping backhand volley from Hewitt gives him 30-40 and a break point, but once again Federer saves himself, scuttling a forehand winner into the top-right corner. Deuce, then. A shanked backhand from Federer gives Hewitt another break point, but Federer produces a drop shot to take us back to Deuce.

1-1 - Once again Hewitt builds a 0-30 lead on Federer's serve, and for the third game in a row Federer has to face break points after Hewitt brings up 15-40 with a backhand volley at the net. Federer saves one with a volley of his own, and saves another when Hewitt stretches to put a crosscourt forehand volley just wide. Deuce. And then two thumping aces give Federer the game. (That green blob is our 'break point saved' icon, in case you were wondering...)

6-2 - A bludgeoning forehand winner down the line gives Federer set point, and the set duly arrives when Hewitt thrashes a backhand return into the tramlines. Federer leads by two sets to love, and Hewitt desperately needs to find inspiration from somewhere.

5-2 - Hewitt holds to 30, but Federer doesn't really look that bothered to be perfectly honest.

4-1 - Hewitt responds with a confident love service game of his own, but the game appears to be up in this set.

3-0 - An attempted lob by Federer is called out at 30-15, but he challenges it and succeeds. Two netted shots from Hewitt hand Federer 30-40 and a double break point, before a forehand into the net from the Australian gives his opponent a 3-0 second-set lead.

1-0 - A backhand winner from Federer that lands right on the baseline brings up 30-30 on Hewitt's serve. Federer follows it up with a wild forehand that lands well wide, but a long forehand from Hewitt takes us to Deuce. A double fault from the Australian hands Federer a first break point of the match, and Hewitt then lashes a backhand into the net to concede the early advantage in this second set. (That's our 'break point' symbol, incidentally.)

8-7 - Deft backhand winner from Federer brings up set point number four!

7-7 - Federer puts forehand down the line wide.

6-6 - Federer puts forehand just long! Lots of unforced errors from the great man.

6-4 - Hewitt slaps forehand into net. Set point Federer!

4-4 - Federer completely shanks backhand. Another mini-break goes begging for the champ.

3-3 - Federer puts backhand long.

2-2 - Federer nets forehand. 'Come on!' shouts Hewitt.

2-0 - Hewitt appears to put backhand fractionally long. It's called out, he challenges it, he wins! Federer can't believe it.

1-0 - Hewitt nets backhand. 1-0 to Federer.

6-5 - A delicate backhand volley puts Federer 40-0 up, and he takes the game thanks to a big serve that Hewitt puts into the net. Hewitt will serve to stay in the set.

5-4 - A great overhead volley puts Federer 30-15 ahead, an ace gives him 40-15 and then another ace brings him the game. Two biggish aces = one ace symbol deployment.

4-3 - A long sliced backhand from Federer takes us to 30-30, but Federer responds with an ace and takes the game with a fine open-handed forehand volley. The ace symbol doesn't get used for every ace, you understand, only the really big 'uns. Otherwise you'd get sick of seeing it and it would lose its ace-tastic value.

3-2 - Federer holds to 15 and is starting to find his stride. A typically artful backhand winner down the line at 30-15 is particularly tasty.

2-1 - Federer seals a love service game with an ace down the centre. That yellow blur on the left is our patented 'ace' icon, in case you were wondering.

1-0 - A strong start from Hewitt, and he moves to 0-30 before Federer produces a first ace of the match and follows it up with an unreturned serve to level the game. Another wicked serve gives him 40-30, before a long forehand return from Hewitt hands the champ the first game. We were on the verge of something interesting for about 15 seconds there.

13:10 - They're knocking up at the moment, as the latecomers make their way to their seats. The sun is shining quite strongly now, and there aren't too many clouds in the sky at the moment. There's a big cloud on Hewitt's horizon though, and its name is Imminent Elimination. Can he pull off the shock of the tournament this afternoon?

12:57 - Federer is yet to drop a set at Wimbledon this year, having brushed aside Dominik Hrbaty of Slovakia, Robin Soderling of Sweden and France's Marc Gicquel in straight sets. Hewitt was taken to five sets by the Netherlands' Robin Haase in round one, before turning in rather more comfortable victories against Albert Montanes of Spain and Italy's Simone Bolelli. Despite Hewitt's pedigree, though, anything other than a Federer win this afternoon will be a big, big shock.

12:45 - Good afternoon and thank-you for joining us for LIVE coverage of this fourth round match between defending champion Roger Federer and 2002 champion Lleyton Hewitt from Centre Court. The players are due on court at 13:00 BST.