Good afternoon and welcome to live coverage of Rafael Nadal against Tomas Berdych from the O2 Arena in London.

GAME, SET AND MATCH NADAL! Nadal almost pulled off a Federer through-the-legs winner in that game, but he is already over the line. Berdych gave his lot, but he ran out of steam in the face of some relentless pressure from the Spanish star. A fantastic effort from Nadal.

SECOND BREAK TO NADAL! Nadal eases 40-15 ahead on Berdych's serve as the Czech player's world slowly begins to collapse all around him. The Spanish player clobbers a forehand wide of the target, but a double fault is enough to hand Nadal the double break. This match is all but over. Nadal looks like he will be playing Andy Murray in the last four.

Berdych's race looks like it could be run for this event. He has battled gamely, but Nadal continues to exert some serious pressure in moving 40-15 clear. The Czech player tucks away a volley at the net to make it 40-30. Berdych somehow claws a ball back over the net as Nadal misses the forehand, but he is not to be denied as he claims the next two points to move 4-1 clear in the second set.

NADAL BREAKS! Nadal moves 0-30 clear, but Berdych is quick to react as a lovely volley takes him to 30-30. A big first serve is knocked into the net by Nadal, but the Czech player wallops a forehand wide of the target as we reach deuce again. Nadal has a break point, but Berdych rescues it with a big serve and volley. He moves to advantage with another piercing first serve, but he knocks a backhand long from the back of the court. Nadal keeps probing and Berdych finally drops serve.

Nadal with four aces so far. Gave Berdych little chance in that game as he unloaded a series of his trademark looping forehands. Too good in this form. No sign of a break yet. Nadal will have to drop a few gears if he is going to lose this match.

Berdych keeping himself well in this match. Just when it seems likely that Nadal is going to break, Berdych seems to come up with the right reply. Another deuce game, but this time the Czech player snags it. We remain on serve, no breaks yet.

Nadal taken to deuce after that frenetic first set. Berdych posing some tough questions of Nadal but, as per usual, the Spanish player has the answers. Some fantastic play as he refuses to be broken. He is ahead in the second set, and looking close to his best form.

SET TO NADAL! Nadal quickly into his stride in the tie-break. Moves 3-0 ahead in winning eight of the previous nine points since his argument with the umpire. A meaty couple of first serves brings the score back to 3-2, but Nadal swings a first serve out wide to move 4-2 ahead and he maintains his charge to the set by claiming the next to move 5-2 ahead. A double fault by Berdych sees the score fall 6-2 in Nadal's favour. Nadal ties it up with a stunning winner down the line for a 7-3 win.

Nadal furious after the umpire called a point out before Berdych challenged. The ball was ruled in, but instead of replaying the point at 15-15, the umpire gives the point to the Czech. Nadal absolutely seething as he argues with the umpire and an official outside of the court. Holds himself together to win the next two points before Berdych converts a winner to tie the game up at deuce. A thumping forehand winner sees Nadal move to advantage before Berdych screws a shot wide. Tie-break.

Berdych is quick out of the traps again to establish a 40-0 lead, but suddenly Nadal is back in it as he moves Berdych around the court with some baseline bullets. Nadal looked good for the point to make it deuce, but Berdych is up to the task as he clobbers a winner with the forehand that whizzes down the line. Super play.

Stunning defence from Nadal to level at 15-15. Berdych hammering the ball, but Nadal keeps going before dropping a shot at the feet of the Czech player that Berdych cannot return. Nadal drills an ace beyond his opponent before whipping a forehand across court that wrong foots Berdych. All of a sudden it is 5-5. Great defence from Nadal at the start of that game.

Berdych looking far from fazed. Really throwing his frame into converting a forehand winner to move 40-15 ahead. Nadal rattles a return into the net from a Berdych serve, and we continue on serve. Berdych was a semi-finalist at the French Open and a finalist at Wimbledon. Nadal serves to stay in the set.

A love game for Nadal on serve. Easiest service game of the match for the world number one, who has spanked away 11 winners so far. Pressure mounting on Berdych to keep coming up with the goods on his serve. A lapse now could cost him the opening set.

A solid start from Berdych in claiming the open two points of the game, but he loses the next before a double fault sees the score move to 30-30. Chance for Nadal at the back of the court, but he rattles the two-handed backhand into the net trying to pass his opponent. He is looking serious when he passes Berdych on the next point to level at deuce before a timely first serve and thumping forehand winner gives the Czech player the game. More resistance from Berdych.

Nadal's mum is in the crowd, and she must be happy with some of her boy's movement. Nadal retaining great patience. Prepared to wait for Berdych to make the errors during the points. Nadal looks the stronger man the longer these rallies go on. Berdych can win only one point as Nadal levels at 3-3.

Some wonderful defence by Berdych. He was staring down the barrel of a gun at 15-40, but somehow got a forehand on the run back over the net. Nadal makes a mess of a return as we return to deuce before a couple of well-placed serves are enough to keep the match on serve. No wonder Berdych is pumping his fist out there.

Nadal's serve is deceptively sharp, as is that forehand which he whips up a storm with it all too easily in leaving Berdych reeling when on the run. Nadal with 77% of his first serves flying in. When that happens, he wins 70% of the points. Berdych claimed only one point in that game. We are level again at 2-2.

Berdych steadies himself well to hold serve on that game, especially after coming so close to breaking Nadal in the previous game. Berdych with two aces in his opening two games. Looks like a full house in for this one again.

Any balls that fall short are brutally whacked away by Nadal. He bludgeons a forehand winner up the line, but Berdych is quickly back on to his case to move 30-15 ahead after Nadal does not find a deep enough shot during a rally. Some stunning tennis by the Czech player as he goes to the net to sink a winning volley and give himself two break points. Nadal saves the first with a blistering forehand and ace on the next brings it to deuce. Nadal turns the screw with some brutal strokes. All level.

A confident start by Berdych. He played one sparkling forehand winner down the line. Seems to be serving well. Nadal tweaked a forehand out in picking up only one point in that game. Important for Berdych to get off to a decent start in this encounter.