Andy Murray loses to Stan Wawrinka 7-6 (7-4) 6-4
Wawrinka will face Federer in Saturday semi-final
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Murray 6-7 (3-7) 1-2 Wawrinka*
England rugby player Danny Cipriani is the crowd tonight, combining a leather biker jacket with some scholarly specs.
He is sat next to former Strictly Come Dancing contestant Kirsty Gallacher, daughter of Ryder Cup legend Bernard, in the celeb pen.
They will be leaning a little closer in now. Murray has taken Wawrinka to deuce from 40-0 down...
Andy Murray with no margin for error now.
Does he still believe that his weekend will include a river taxi to the O2 Arena?
He keeps that possibility alive as he holds off Wawrinka, clinging onto serve to 30.
Murray is on the ropes though, no doubt.
Image source, AFPStan Wawrinka's backhand - the weapon that wrecked Novak Djokovic's chances in the French Open - is starting to spray winners.
Two sickly sweet strikes off that wing zip away for clean winners as the Swiss backs up the break with a hold to love.
Might Andy Murray's mind be slipping towards an area the size of Belgium and Great Britain's upcoming Davis Cup final?
Murray 6-7 (3-7) 0-1 Wawrinka*
Only one of Andy Murray's eight wins over Stan Wawrinka has come from a set down.
He needs to turn this tanker around sharply.
Wawrinka has 15-30 and then 30-40 and break point as he smokes a backhand down the line.
Trademark Stan and a chance to apply more boot to bottom.
Murray nets! He is looking at the rough end of a break and a set down.
Jamie Delgado
Former Great Britain Davis Cup player
Image source, AFPHe fought so hard and got himself in a good position, but unforced errors costs him. It was a disappointing end to the set.
Russell Fuller
BBC tennis correspondent
Murray really did go AWOL from 4-2 up and he's going to have to do it the hard way if he's going to qualify for the semi-finals.
*Murray 6-7 (4-7) Wawrinka
Image source, Getty ImagesAndy Murray dashes his racquet to the floor.
Another basic error. Stan Wawrinka has 6-4 and two set points.
He only needs the one. Murray gets lucky with a net cord that just about makes it over, but he fails to make the most of his get-out-of-jail card, cuffing a lob wide.
*Murray 6-6 (4-5) Wawrinka
Initiative handed back.
Andy Murray twangs into the tape on the forehand wing as he attempts to go cross court.
Stan outfoxes Murray with a cunning second serve. Murray plonks wide in the next rally and suddenly the momentum has shifted.
Wawrinka 5-4 to the good. On serve, but mojo with Stan.
*Murray 6-6 (4-2) Wawrinka
Image source, Getty ImagesThis is tight-rope knife-edge tennis.
Wawrinka holds for 2-2. A weakling of second serve on the next though - and Murray's roundhouse backhand return finds the mark, streaking away for a winner.
Murray 3-2 up with the mini-break.
And he consolidates on serve for a 4-2 lead. Has Stan gone back into his shell?
Murray 6-6 (2-1) Wawrinka*
Stan Wawrinka with an ace on the opening point. Or is it? Yep, approved on video review.
1-0 to the Swiss.
Murray misses with his first serve. A mammoth rally, Murray chasing the rubber off his soles and he finally draws the error from Wawrinka.
And he wins the next point in more straightforward style. 2-1 Murray and on serve.
Russell Fuller
BBC tennis correspondent
Wawrinka has won 33 tie breaks and lost 12 this year.
And, after 55 minute of premium tennis and via a Murray ace, we are into a tie-break.
Stan to serve first.
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Image source, ReutersShohidur Rahman, external: Would it be that much of a surprise to see Wawrinka beat Murray? Fact is he's a better player now. #bbctennis, external
Paul Staveley, external: Murray has the game to beat anyone but the big three. Their mental strength is all that separates them from him though.
Stan Wawrinka clocks back in.
He holds to love to show that he is over that heartache of serving for the set and failing to seal the deal.
During a break after one game, the 02 crowd were treated to a bit of the Manic Street Preachers on the arena's sound system - 'If You Tolerate this..."
The song reached number one in 1998, when Murray was 11 and Wawrinka just into his teens.
Image source, PAStan Wawrinka has been ticked off with some in the crowd expressing their support for Andy Murray just as he was tossing up in the last game.
His mood does not look like it has improved as Murray tickles in a delicate fluttering drop-shot to on his way to the game.
The Scot has pulled back up alongside the Swiss on the scoreboard.
Jamie Delgado
Former Great Britain Davis Cup player
Incredible defence from Murray, he was on full stretch for six or seven shots in a row. Andy read the game perfectly. Great movement, great fight.
*Murray 4-5 Wawrinka
Image source, PAOh my.
What a rally. Andy Murray seems to be at Stan Wawrinka's mercy on at least two occasions, but each time he did just enough as Wawrinka did not quite commit.
And finally Wawrinka flops a lazy volley into the floor, allowing Murray to scamper onto the ball to ping away a winner into the unguarded open court.
Murray 3-5 Wawrinka*
Andy Murray has a look down the line on the forehand.
He takes up the challenge. But it is over-cooked and Murray's features rearrange into a grimace.
Deuce.
But a deft backhand volley dies perfectly to give Murray a second break point.