Hello and welcome to LIVE updates of the ATP World Tour finals round-robin clash between six-time champion, Roger Federer and debutant at the event, Kevin Anderson. The South African is already into the last four after picking up two wins from two, but Federer still has some work to do. The Swiss Maestro will progress if he wins a set.

GAME, SET AND MATCH! - ANDERSON 4-6 3-6 FEDERER. Roger Federer produces his best display of the week so far to see off in-form Kevin Anderson in straight sets in one hour and 17 minutes. The Swiss was just too good, utilising a short, slow slice time and time again to unsettle the South African.

The world No.3 won it on his third match point from deuce, breaking Big Kev once again after the gentle giant had fought hard to fend off the first two and make deuce.

Federer will now top the pool and should avoid Novak Djokovic in the last four.

ANDERSON 4-6 3-5 FEDERER. No slip-up this time. Federer consolidates with a hold to love and is one game away from victory.

BREAK! - ANDERSON 4-6 3-4 FEDERER. Ando slams down ace number 10 for a 30-15 lead - but then it goes pear-shaped. Federer cranks up the heat and poses some tricky questions to snare the first BP of the set. Anderson tries to dig in but Federer's depth to the far corner is just too good and Big Kev can only slap a horrible shot into the net. The Swiss is now in a strong position to see this out and top the group.

ANDERSON 4-6 3-3 FEDERER. When they get into some excellent exchanges there is only ever one winner. Federer dominates again in the concluding point as Anderson flashes long after picking up just the one point on the Swiss' serve.

ANDERSON 4-6 3-2 FEDERER. The ace count keeps rising at a consistent rate for Anderson (nine now) and it's been key to him regaining his momentum on serve after Federer tore it to shreds at the end of the opening set.

ANDERSON 4-6 2-2 FEDERER. Roger keeps Big Kev at arm's length as he serves big and lands a third ace of the night to hold to 30. All square. The calm before the storm in this second set? Let's hope so.

ANDERSON 4-6 2-1 FEDERER. Roger balloons a very loose forehand way out of court and hands the game to Ando. The South African's serve is ticking over nicely again as he easily maintains the scoreboard advantage with a hold to 15, clocking up ace no.7 along the way.

ANDERSON 4-6 1-1 FEDERER. The world No.3 is looking like a man who knows his game-plan is working a treat. He continues to slice and try to move the towering Anderson around court. The case in point arrives on game-point when he lures the South African in with drop shot before coolly prodding a winner into the empty court.

ANDERSON 4-6 1-0 FEDERER. Anderson is troubled by the short, low slice once more, but Roger can't get enough on the first serves to stop the South African from picking up a much-needed hold to start Set 2 in the right manner.

SET! - ANDERSON 4-6 FEDERER. The six-time champion does it the hard way, coming back from triple break point down to serve out the set and book his place in the last four.

BREAK! - ANDERSON 4-5 FEDERER. That is magnificent. Federer ups the ante again, causing Anderson all sorts of problems with some devilish low slice. The Swiss racks up triple break point, but needs just the one as he breaks to love once again with a sublime drop volley.

One more game and Federer is in the semis.

BREAK! - ANDERSON 4-4 FEDERER. Wow. No one was expecting that, and even less so after Fed moved 30-0 to the good. The Swiss has game point at 40-30 but is caught out by a lovely return winner from his opponent. From there the world No.3 surprisingly unravels and misfires to hand Big Kev the break back.

BREAK! - ANDERSON 3-4 FEDERER. Anderson coughs up two double faults and completely implodes out of the blue as Federer emphatically breaks the South African to seize the initiative. That's the first time Anderson has lost his serve this week.

ANDERSON 3-3 FEDERER. All square. Fed hustles to get himself out of a hole from 0-30. A lovely dropshot to create the opening for a backhand pass up the line seals the deal with real swagger. That got the crowd cooing.