Serena Williams: "I didn't have a great practice so I was a little nervous, but I was able to hang in there. I can't believe I'm in the semis - it's probably not as good as the first time, but it never gets old, it's always something I want to do. Me and Venus are best friends and do everything together but it was a tough match for her and there's always next year."

Serena 7-5 6-3 Li
Williams moves into a 0-30 lead but Li's still throwing punches, forcing Serena into a tame forehand into the bottom of the net. But Williams has a match point as Li misses on the scamper and Li hands it to her on a plate, hooking a forehand wide. Li appeared to have challenged there but seemed to decided against it as Serena rushed towards the net.

Serena 7-5 5-3 Li*
Big backhand return from Li makes it 15-15 - she's still scrapping at least - and the Chinese woman makes it 15-30 with a couple of coruscating strokes on the backhand wing. Sensational stuff! Great scrambling by Li behind the baseline and she creates two break points with another dipping backhand that has Serena clawing at thin air. Williams saves one with another howitzer serve before Li wins a superb rally, scrambling well again before wrong-footing Williams at the net with a backhand winner. She's alive...

*Serena 7-5 5-2 Li
A challenge from Williams but Li's pass did catch the line. Li sticks a backhand long and does it again to make it 15-30. Li with a backhand into the net and Serena has two more break points - Li dredges up a bomb to save the first before serving up another double. That first serve was in, but she opted not to challenge...

Serena 7-5 4-2 Li*
Serena balloons a forehand long to go 0-15 down before sending down a 113mph serve to even things up. Ace number 11 makes it 40-15 and Li can't cope with this sort of heat from the Williams serve, it's another straightforward hold.

*Serena 7-5 3-2 Li
New balls and Li has first go with them. She finds them a bit too juicy on the second and third points, putting groundstrokes long, and Serena creates two break points. She only needs one of them, Li plonking a forehand into the net...

Serena 7-5 2-2 Li*
Another ace from Serena to kick off the game, that's her 10th today, but that's a cracking backhand volley from Li, leaving Serena stranded as the ball is deadened by the Centre Court grass. That's not too clever though, the Chinese woman duffing a backhand volley into the net to hand Williams the game.

*Serena 7-5 1-2 Li
Some stats from the first set: Serena won 89% of points on her first serve while Li won 76%. Serena powered down seven aces compared to two from Li and only made five unforced errors while the Chinese player produced 11. Serena chokes a backhand return long to hand Li a 40-15 lead on serve and another forehand long is greeted by bright sunshine on Centre - not the greatest match this, both players making plenty of mistakes and quality rallies at a premium.

Serena 7-5 1-1 Li*
Williams moves into a 40-0 lead with ace number eight out wide and seals the game with another...

*Serena 7-5 0-1 Li
Li looks to have regrouped well, moving into a 40-15 lead, but follows up with another unforced error. What a rally that was - and there haven't been too many - both players working the Centre Court crowd into a lather with angled, cross-court forehands before Williams nails the winner. But Li rallies well, refusing to buckle under some more bombs from Serena and eventually forcing her into a forehand into the net.
* denotes next server

Tracy Austin on BBC TV: "Li lost her nerve (at 40-0 up in the 11th game) and became very tentative. It doesn't take much when Serena is serving this well and it does put so much pressure on you."

Serena 7-5 Li*
Serena misses the sideline with an attempted backhand pass before Li goes long with a rather desperate backhand. Late call again as Li misses with a forehand and Williams forces another mistake on the forehand wing to set up two set points... Serena only needs one of them, Li managing to block a return back only for her rival to leave her rooted with a backhand down the line. Li only blinked once in that set but that was all Williams needed.

*Serena 6-5 Li
Li's entourage getting animated now as first Li sends an ace down the T and then stoops and threads a backhand down the line to make it 40-0. Li plonks a forehand into the net to make it 40-15 before tugging a forehand long and wide to give Serena a sniff and she follows up with a double-fault... that's pressure messing with you, everything getting tight... another double hands Serena the advantage and Li puts a forehand volley long to gift Serena the break - meltdown, Serena will serve for the set...

Serena 5-5 Li*
Sorry, just got booted out again, but it was another Serena hold with another couple of aces thrown in...

*Serena 4-5 Li
Big unforced error from Li, ballooning a forehand long, but she's really holding her own in some of these baseline exchanges, using that tremendous racquet-head speed to generate plenty of wheels. Late call as Serena hooks a forehand return wide and the American immediately challenges - no dice, it was out. Li pulls out a plum and it's another hold...

Serena 4-4 Li*
A sniff for Li at 15-30 but the Chinese woman first puts a forehand long before Williams slams the door on her fingers with an ace down the middle. Another hold from Williams, although Li is hanging on in there.

British number one Anne Keothavong on BBC 5 live Sports Extra: "Serena is... in Serena's world. You get hellos out of Serena and Venus, but they travel with a huge entourage. They never practice with any other players. It was interesting though, on the morning of meeting the Queen on Thursday, just watching her interact with Venus, Jelena Jankovic and Caroline Wozniacki. They were all dressed up, while us British players were told to just wear tracksuits! It was surreal, with Navratilova and Billie Jean King, all of us practicing our curtseys."

*Serena 3-4 Li
A roar of frustration from Serena as she finds the net with a forehand before Li gets herself in a real pickle, misjudging a Serena moon-ball and finding the net with a tame-looking forehand. Williams gets another point back but goes long with a forehand to hand Li another hold.

Serena 3-3 Li*
Li finding plenty of depth with her groundstrokes and holding her own in the hitting battle. Ripper of a forehand winner from Williams to make it 15-15 before Li misses the sideline with a backhand. Serena sends her third ace, I believe, past the statue-esque Li and follows up with another. Not much coming back on the Williams serve.

*Serena 2-3 Li
Serena steps in and laces a drive-volley past her Chinese opponent but Li hits back well, threading a backhand pass down the line. Double fault from Li and Serena has two break points out of the blue - Li gets a serve to rear up at Williams, that's one saved, and that's very gritty from Li, hitting the lines with her forehand twice to make it deuce. Crackerjack backhand winner from Li and Serena tugs a backhand return wide to hand Li the game - big hold that, another upset on the cards?

Serena 2-2 Li*
Cloud cover over Centre again but it's still pretty muggy out there. Brutal from Serena again, Li only able to dink the return back and the American putting away the forehand winner. Serena with an ace, her 70th of the tournament, and there's another. Li goes long with a forehand return, not a sniff on either woman's serve so far.

*Serena 1-2 Li
Good, penetrating second serve from Li to make it 30-0 and she opens up the court on the next point with one out wide before putting away the forehand winner down the middle. Serena gets a point back but Li pulls out another big first serve to hold with some ease again. No chances on return of serve so far...

Serena 1-1 Li*
Li is unable to chase down a cross-court forehand from Williams before Williams leaves the Chinese woman rooted with a savage forehand on the gallop. Li feels the power of Serena again and that's another easy hold.

*Serena 0-1 Li
It's Li, who trails Serena 4-1 in head-to-heads, to serve first and she races into a 40-15 lead. And that's a comfortable hold, with Williams going long with a forehand at 40-15.
* denotes next server

1507: So two shocks in the first two semi-finals and the chance of an all-Williams final over - just Serena left to fly the flag for the family as she takes on Li Na.